ETH Price: $2,525.80 (-5.23%)

Transaction Decoder

Block:
21743979 at Jan-31-2025 10:41:23 AM +UTC
Transaction Fee:
0.000727324201611216 ETH $1.84
Gas Used:
182,061 Gas / 3.994947856 Gwei

Emitted Events:

12 ValidatorShareProxy.0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef( 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef, 0x0000000000000000000000000000000000000000000000000000000000000000, 0x0000000000000000000000001aa4afdfe4211584dbff80ba03e6bd6505089035, 0000000000000000000000000000000000000000000000057016ac2660a95a1d )
13 StakingInfo.ShareMinted( validatorId=118, user=[Sender] 0x1aa4afdfe4211584dbff80ba03e6bd6505089035, amount=100310552631113767453, tokens=100310552631113767453 )
14 StakingInfo.StakeUpdate( validatorId=118, nonce=1677, newAmount=1353301279170518195843128 )
15 StakingInfo.DelegatorRestaked( validatorId=118, user=[Sender] 0x1aa4afdfe4211584dbff80ba03e6bd6505089035, totalStaked=7236981866430641105634 )

Account State Difference:

  Address   Before After State Difference Code
0x1AA4afDF...505089035
0.198734080880067205 Eth
Nonce: 92
0.198006756678455989 Eth
Nonce: 93
0.000727324201611216
0x3EDBF7E0...409364269
(Titan Builder)
5.801858253285123822 Eth5.802313405785123822 Eth0.0004551525
0x5e3Ef299...e8c13D908
(Polygon (Matic): PoS Staking Contract)
0xa59C847B...A71A7512B
(Polygon (Matic): Staking Info)

Execution Trace

ValidatorShareProxy.CALL( )
  • Registry.STATICCALL( )
  • ValidatorShare.DELEGATECALL( )
    • StakeManagerProxy.7ed4b27c( )
    • StakeManagerProxy.7f4b4323( )
      • StakeManager.delegatedAmount( validatorId=118 ) => ( 1350650968617887082075675 )
      • StakeManagerProxy.9ff11500( )
      • StakingInfo.logShareMinted( validatorId=118, user=0x1AA4afDFE4211584Dbff80bA03e6Bd6505089035, amount=100310552631113767453, tokens=100310552631113767453 )
        • Registry.STATICCALL( )
        • StakeManagerProxy.35aa2e44( )
          • StakeManager.validators( 118 ) => ( amount=2550000000000000000000, reward=785988616150473052177, activationEpoch=11448, deactivationEpoch=0, jailTime=0, signer=0x5fFD4EFfD8E476C72FddC75BcD31f421001F9Ce6, contractAddress=0x3EDBF7E027D280BCd8126a87f382941409364269, status=1, commissionRate=3, lastCommissionUpdate=40943, delegatorsReward=1, delegatedAmount=1350751279170518195843128, initialRewardPerStake=3043919065280036352677896 )
          • StakingInfo.logStakeUpdate( validatorId=118 )
            • Registry.STATICCALL( )
            • StakeManagerProxy.35aa2e44( )
              • StakeManager.validators( 118 ) => ( amount=2550000000000000000000, reward=785988616150473052177, activationEpoch=11448, deactivationEpoch=0, jailTime=0, signer=0x5fFD4EFfD8E476C72FddC75BcD31f421001F9Ce6, contractAddress=0x3EDBF7E027D280BCd8126a87f382941409364269, status=1, commissionRate=3, lastCommissionUpdate=40943, delegatorsReward=1, delegatedAmount=1350751279170518195843128, initialRewardPerStake=3043919065280036352677896 )
              • Registry.STATICCALL( )
              • StakeManagerProxy.35aa2e44( )
                • StakeManager.validators( 118 ) => ( amount=2550000000000000000000, reward=785988616150473052177, activationEpoch=11448, deactivationEpoch=0, jailTime=0, signer=0x5fFD4EFfD8E476C72FddC75BcD31f421001F9Ce6, contractAddress=0x3EDBF7E027D280BCd8126a87f382941409364269, status=1, commissionRate=3, lastCommissionUpdate=40943, delegatorsReward=1, delegatedAmount=1350751279170518195843128, initialRewardPerStake=3043919065280036352677896 )
                • ValidatorShareProxy.STATICCALL( )
                  • Registry.STATICCALL( )
                  • ValidatorShare.DELEGATECALL( )
                  • StakeManagerProxy.7f4b4323( )
                    • StakeManager.delegatedAmount( validatorId=118 ) => ( 1350751279170518195843128 )
                    • StakingInfo.logDelegatorRestaked( validatorId=118, user=0x1AA4afDFE4211584Dbff80bA03e6Bd6505089035, totalStaked=7236981866430641105634 )
                      • Registry.STATICCALL( )
                      • StakeManagerProxy.35aa2e44( )
                        • StakeManager.validators( 118 ) => ( amount=2550000000000000000000, reward=785988616150473052177, activationEpoch=11448, deactivationEpoch=0, jailTime=0, signer=0x5fFD4EFfD8E476C72FddC75BcD31f421001F9Ce6, contractAddress=0x3EDBF7E027D280BCd8126a87f382941409364269, status=1, commissionRate=3, lastCommissionUpdate=40943, delegatorsReward=1, delegatedAmount=1350751279170518195843128, initialRewardPerStake=3043919065280036352677896 )
                          File 1 of 6: ValidatorShareProxy
                          // File: openzeppelin-solidity/contracts/ownership/Ownable.sol
                          
                          pragma solidity ^0.5.2;
                          
                          /**
                           * @title Ownable
                           * @dev The Ownable contract has an owner address, and provides basic authorization control
                           * functions, this simplifies the implementation of "user permissions".
                           */
                          contract Ownable {
                              address private _owner;
                          
                              event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
                          
                              /**
                               * @dev The Ownable constructor sets the original `owner` of the contract to the sender
                               * account.
                               */
                              constructor () internal {
                                  _owner = msg.sender;
                                  emit OwnershipTransferred(address(0), _owner);
                              }
                          
                              /**
                               * @return the address of the owner.
                               */
                              function owner() public view returns (address) {
                                  return _owner;
                              }
                          
                              /**
                               * @dev Throws if called by any account other than the owner.
                               */
                              modifier onlyOwner() {
                                  require(isOwner());
                                  _;
                              }
                          
                              /**
                               * @return true if `msg.sender` is the owner of the contract.
                               */
                              function isOwner() public view returns (bool) {
                                  return msg.sender == _owner;
                              }
                          
                              /**
                               * @dev Allows the current owner to relinquish control of the contract.
                               * It will not be possible to call the functions with the `onlyOwner`
                               * modifier anymore.
                               * @notice Renouncing ownership will leave the contract without an owner,
                               * thereby removing any functionality that is only available to the owner.
                               */
                              function renounceOwnership() public onlyOwner {
                                  emit OwnershipTransferred(_owner, address(0));
                                  _owner = address(0);
                              }
                          
                              /**
                               * @dev Allows the current owner to transfer control of the contract to a newOwner.
                               * @param newOwner The address to transfer ownership to.
                               */
                              function transferOwnership(address newOwner) public onlyOwner {
                                  _transferOwnership(newOwner);
                              }
                          
                              /**
                               * @dev Transfers control of the contract to a newOwner.
                               * @param newOwner The address to transfer ownership to.
                               */
                              function _transferOwnership(address newOwner) internal {
                                  require(newOwner != address(0));
                                  emit OwnershipTransferred(_owner, newOwner);
                                  _owner = newOwner;
                              }
                          }
                          
                          // File: contracts/common/misc/ProxyStorage.sol
                          
                          pragma solidity ^0.5.2;
                          
                          
                          contract ProxyStorage is Ownable {
                              address internal proxyTo;
                          }
                          
                          // File: contracts/common/misc/ERCProxy.sol
                          
                          /*
                           * SPDX-License-Identitifer:    MIT
                           */
                          
                          pragma solidity ^0.5.2;
                          
                          // See https://github.com/ethereum/EIPs/blob/master/EIPS/eip-897.md
                          
                          interface ERCProxy {
                              function proxyType() external pure returns (uint256 proxyTypeId);
                              function implementation() external view returns (address codeAddr);
                          }
                          
                          // File: contracts/common/misc/DelegateProxy.sol
                          
                          pragma solidity ^0.5.2;
                          
                          
                          
                          contract DelegateProxy is ERCProxy {
                              function proxyType() external pure returns (uint256 proxyTypeId) {
                                  // Upgradeable proxy
                                  proxyTypeId = 2;
                              }
                          
                              function implementation() external view returns (address);
                          
                              function delegatedFwd(address _dst, bytes memory _calldata) internal {
                                  // solium-disable-next-line security/no-inline-assembly
                                  assembly {
                                      let result := delegatecall(
                                          sub(gas, 10000),
                                          _dst,
                                          add(_calldata, 0x20),
                                          mload(_calldata),
                                          0,
                                          0
                                      )
                                      let size := returndatasize
                          
                                      let ptr := mload(0x40)
                                      returndatacopy(ptr, 0, size)
                          
                                      // revert instead of invalid() bc if the underlying call failed with invalid() it already wasted gas.
                                      // if the call returned error data, forward it
                                      switch result
                                          case 0 {
                                              revert(ptr, size)
                                          }
                                          default {
                                              return(ptr, size)
                                          }
                                  }
                              }
                          }
                          
                          // File: contracts/common/misc/UpgradableProxy.sol
                          
                          pragma solidity ^0.5.2;
                          
                          
                          contract UpgradableProxy is DelegateProxy {
                              event ProxyUpdated(address indexed _new, address indexed _old);
                              event OwnerUpdate(address _new, address _old);
                          
                              bytes32 constant IMPLEMENTATION_SLOT = keccak256("matic.network.proxy.implementation");
                              bytes32 constant OWNER_SLOT = keccak256("matic.network.proxy.owner");
                          
                              constructor(address _proxyTo) public {
                                  setOwner(msg.sender);
                                  setImplementation(_proxyTo);
                              }
                          
                              function() external payable {
                                  // require(currentContract != 0, "If app code has not been set yet, do not call");
                                  // Todo: filter out some calls or handle in the end fallback
                                  delegatedFwd(loadImplementation(), msg.data);
                              }
                          
                              modifier onlyProxyOwner() {
                                  require(loadOwner() == msg.sender, "NOT_OWNER");
                                  _;
                              }
                          
                              function owner() external view returns(address) {
                                  return loadOwner();
                              }
                          
                              function loadOwner() internal view returns(address) {
                                  address _owner;
                                  bytes32 position = OWNER_SLOT;
                                  assembly {
                                      _owner := sload(position)
                                  }
                                  return _owner;
                              }
                          
                              function implementation() external view returns (address) {
                                  return loadImplementation();
                              }
                          
                              function loadImplementation() internal view returns(address) {
                                  address _impl;
                                  bytes32 position = IMPLEMENTATION_SLOT;
                                  assembly {
                                      _impl := sload(position)
                                  }
                                  return _impl;
                              }
                          
                              function transferOwnership(address newOwner) public onlyProxyOwner {
                                  require(newOwner != address(0), "ZERO_ADDRESS");
                                  emit OwnerUpdate(newOwner, loadOwner());
                                  setOwner(newOwner);
                              }
                          
                              function setOwner(address newOwner) private {
                                  bytes32 position = OWNER_SLOT;
                                  assembly {
                                      sstore(position, newOwner)
                                  }
                              }
                          
                              function updateImplementation(address _newProxyTo) public onlyProxyOwner {
                                  require(_newProxyTo != address(0x0), "INVALID_PROXY_ADDRESS");
                                  require(isContract(_newProxyTo), "DESTINATION_ADDRESS_IS_NOT_A_CONTRACT");
                          
                                  emit ProxyUpdated(_newProxyTo, loadImplementation());
                                  
                                  setImplementation(_newProxyTo);
                              }
                          
                              function updateAndCall(address _newProxyTo, bytes memory data) payable public onlyProxyOwner {
                                  updateImplementation(_newProxyTo);
                          
                                  (bool success, bytes memory returnData) = address(this).call.value(msg.value)(data);
                                  require(success, string(returnData));
                              }
                          
                              function setImplementation(address _newProxyTo) private {
                                  bytes32 position = IMPLEMENTATION_SLOT;
                                  assembly {
                                      sstore(position, _newProxyTo)
                                  }
                              }
                              
                              function isContract(address _target) internal view returns (bool) {
                                  if (_target == address(0)) {
                                      return false;
                                  }
                          
                                  uint256 size;
                                  assembly {
                                      size := extcodesize(_target)
                                  }
                                  return size > 0;
                              }
                          }
                          
                          // File: contracts/common/governance/IGovernance.sol
                          
                          pragma solidity ^0.5.2;
                          
                          interface IGovernance {
                              function update(address target, bytes calldata data) external;
                          }
                          
                          // File: contracts/common/governance/Governable.sol
                          
                          pragma solidity ^0.5.2;
                          
                          
                          contract Governable {
                              IGovernance public governance;
                          
                              constructor(address _governance) public {
                                  governance = IGovernance(_governance);
                              }
                          
                              modifier onlyGovernance() {
                                  require(
                                      msg.sender == address(governance),
                                      "Only governance contract is authorized"
                                  );
                                  _;
                              }
                          }
                          
                          // File: contracts/root/withdrawManager/IWithdrawManager.sol
                          
                          pragma solidity ^0.5.2;
                          
                          contract IWithdrawManager {
                              function createExitQueue(address token) external;
                          
                              function verifyInclusion(
                                  bytes calldata data,
                                  uint8 offset,
                                  bool verifyTxInclusion
                              ) external view returns (uint256 age);
                          
                              function addExitToQueue(
                                  address exitor,
                                  address childToken,
                                  address rootToken,
                                  uint256 exitAmountOrTokenId,
                                  bytes32 txHash,
                                  bool isRegularExit,
                                  uint256 priority
                              ) external;
                          
                              function addInput(
                                  uint256 exitId,
                                  uint256 age,
                                  address utxoOwner,
                                  address token
                              ) external;
                          
                              function challengeExit(
                                  uint256 exitId,
                                  uint256 inputId,
                                  bytes calldata challengeData,
                                  address adjudicatorPredicate
                              ) external;
                          }
                          
                          // File: contracts/common/Registry.sol
                          
                          pragma solidity ^0.5.2;
                          
                          
                          
                          
                          contract Registry is Governable {
                              // @todo hardcode constants
                              bytes32 private constant WETH_TOKEN = keccak256("wethToken");
                              bytes32 private constant DEPOSIT_MANAGER = keccak256("depositManager");
                              bytes32 private constant STAKE_MANAGER = keccak256("stakeManager");
                              bytes32 private constant VALIDATOR_SHARE = keccak256("validatorShare");
                              bytes32 private constant WITHDRAW_MANAGER = keccak256("withdrawManager");
                              bytes32 private constant CHILD_CHAIN = keccak256("childChain");
                              bytes32 private constant STATE_SENDER = keccak256("stateSender");
                              bytes32 private constant SLASHING_MANAGER = keccak256("slashingManager");
                          
                              address public erc20Predicate;
                              address public erc721Predicate;
                          
                              mapping(bytes32 => address) public contractMap;
                              mapping(address => address) public rootToChildToken;
                              mapping(address => address) public childToRootToken;
                              mapping(address => bool) public proofValidatorContracts;
                              mapping(address => bool) public isERC721;
                          
                              enum Type {Invalid, ERC20, ERC721, Custom}
                              struct Predicate {
                                  Type _type;
                              }
                              mapping(address => Predicate) public predicates;
                          
                              event TokenMapped(address indexed rootToken, address indexed childToken);
                              event ProofValidatorAdded(address indexed validator, address indexed from);
                              event ProofValidatorRemoved(address indexed validator, address indexed from);
                              event PredicateAdded(address indexed predicate, address indexed from);
                              event PredicateRemoved(address indexed predicate, address indexed from);
                              event ContractMapUpdated(bytes32 indexed key, address indexed previousContract, address indexed newContract);
                          
                              constructor(address _governance) public Governable(_governance) {}
                          
                              function updateContractMap(bytes32 _key, address _address) external onlyGovernance {
                                  emit ContractMapUpdated(_key, contractMap[_key], _address);
                                  contractMap[_key] = _address;
                              }
                          
                              /**
                               * @dev Map root token to child token
                               * @param _rootToken Token address on the root chain
                               * @param _childToken Token address on the child chain
                               * @param _isERC721 Is the token being mapped ERC721
                               */
                              function mapToken(
                                  address _rootToken,
                                  address _childToken,
                                  bool _isERC721
                              ) external onlyGovernance {
                                  require(_rootToken != address(0x0) && _childToken != address(0x0), "INVALID_TOKEN_ADDRESS");
                                  rootToChildToken[_rootToken] = _childToken;
                                  childToRootToken[_childToken] = _rootToken;
                                  isERC721[_rootToken] = _isERC721;
                                  IWithdrawManager(contractMap[WITHDRAW_MANAGER]).createExitQueue(_rootToken);
                                  emit TokenMapped(_rootToken, _childToken);
                              }
                          
                              function addErc20Predicate(address predicate) public onlyGovernance {
                                  require(predicate != address(0x0), "Can not add null address as predicate");
                                  erc20Predicate = predicate;
                                  addPredicate(predicate, Type.ERC20);
                              }
                          
                              function addErc721Predicate(address predicate) public onlyGovernance {
                                  erc721Predicate = predicate;
                                  addPredicate(predicate, Type.ERC721);
                              }
                          
                              function addPredicate(address predicate, Type _type) public onlyGovernance {
                                  require(predicates[predicate]._type == Type.Invalid, "Predicate already added");
                                  predicates[predicate]._type = _type;
                                  emit PredicateAdded(predicate, msg.sender);
                              }
                          
                              function removePredicate(address predicate) public onlyGovernance {
                                  require(predicates[predicate]._type != Type.Invalid, "Predicate does not exist");
                                  delete predicates[predicate];
                                  emit PredicateRemoved(predicate, msg.sender);
                              }
                          
                              function getValidatorShareAddress() public view returns (address) {
                                  return contractMap[VALIDATOR_SHARE];
                              }
                          
                              function getWethTokenAddress() public view returns (address) {
                                  return contractMap[WETH_TOKEN];
                              }
                          
                              function getDepositManagerAddress() public view returns (address) {
                                  return contractMap[DEPOSIT_MANAGER];
                              }
                          
                              function getStakeManagerAddress() public view returns (address) {
                                  return contractMap[STAKE_MANAGER];
                              }
                          
                              function getSlashingManagerAddress() public view returns (address) {
                                  return contractMap[SLASHING_MANAGER];
                              }
                          
                              function getWithdrawManagerAddress() public view returns (address) {
                                  return contractMap[WITHDRAW_MANAGER];
                              }
                          
                              function getChildChainAndStateSender() public view returns (address, address) {
                                  return (contractMap[CHILD_CHAIN], contractMap[STATE_SENDER]);
                              }
                          
                              function isTokenMapped(address _token) public view returns (bool) {
                                  return rootToChildToken[_token] != address(0x0);
                              }
                          
                              function isTokenMappedAndIsErc721(address _token) public view returns (bool) {
                                  require(isTokenMapped(_token), "TOKEN_NOT_MAPPED");
                                  return isERC721[_token];
                              }
                          
                              function isTokenMappedAndGetPredicate(address _token) public view returns (address) {
                                  if (isTokenMappedAndIsErc721(_token)) {
                                      return erc721Predicate;
                                  }
                                  return erc20Predicate;
                              }
                          
                              function isChildTokenErc721(address childToken) public view returns (bool) {
                                  address rootToken = childToRootToken[childToken];
                                  require(rootToken != address(0x0), "Child token is not mapped");
                                  return isERC721[rootToken];
                              }
                          }
                          
                          // File: contracts/staking/validatorShare/ValidatorShareProxy.sol
                          
                          pragma solidity ^0.5.2;
                          
                          
                          
                          contract ValidatorShareProxy is UpgradableProxy {
                              constructor(address _registry) public UpgradableProxy(_registry) {}
                          
                              function loadImplementation() internal view returns (address) {
                                  return Registry(super.loadImplementation()).getValidatorShareAddress();
                              }
                          }

                          File 2 of 6: StakingInfo
                          // File: contracts/common/governance/IGovernance.sol
                          
                          pragma solidity ^0.5.2;
                          
                          interface IGovernance {
                              function update(address target, bytes calldata data) external;
                          }
                          
                          // File: contracts/common/governance/Governable.sol
                          
                          pragma solidity ^0.5.2;
                          
                          
                          contract Governable {
                              IGovernance public governance;
                          
                              constructor(address _governance) public {
                                  governance = IGovernance(_governance);
                              }
                          
                              modifier onlyGovernance() {
                                  require(
                                      msg.sender == address(governance),
                                      "Only governance contract is authorized"
                                  );
                                  _;
                              }
                          }
                          
                          // File: contracts/root/withdrawManager/IWithdrawManager.sol
                          
                          pragma solidity ^0.5.2;
                          
                          contract IWithdrawManager {
                              function createExitQueue(address token) external;
                          
                              function verifyInclusion(
                                  bytes calldata data,
                                  uint8 offset,
                                  bool verifyTxInclusion
                              ) external view returns (uint256 age);
                          
                              function addExitToQueue(
                                  address exitor,
                                  address childToken,
                                  address rootToken,
                                  uint256 exitAmountOrTokenId,
                                  bytes32 txHash,
                                  bool isRegularExit,
                                  uint256 priority
                              ) external;
                          
                              function addInput(
                                  uint256 exitId,
                                  uint256 age,
                                  address utxoOwner,
                                  address token
                              ) external;
                          
                              function challengeExit(
                                  uint256 exitId,
                                  uint256 inputId,
                                  bytes calldata challengeData,
                                  address adjudicatorPredicate
                              ) external;
                          }
                          
                          // File: contracts/common/Registry.sol
                          
                          pragma solidity ^0.5.2;
                          
                          
                          
                          
                          contract Registry is Governable {
                              // @todo hardcode constants
                              bytes32 private constant WETH_TOKEN = keccak256("wethToken");
                              bytes32 private constant DEPOSIT_MANAGER = keccak256("depositManager");
                              bytes32 private constant STAKE_MANAGER = keccak256("stakeManager");
                              bytes32 private constant VALIDATOR_SHARE = keccak256("validatorShare");
                              bytes32 private constant WITHDRAW_MANAGER = keccak256("withdrawManager");
                              bytes32 private constant CHILD_CHAIN = keccak256("childChain");
                              bytes32 private constant STATE_SENDER = keccak256("stateSender");
                              bytes32 private constant SLASHING_MANAGER = keccak256("slashingManager");
                          
                              address public erc20Predicate;
                              address public erc721Predicate;
                          
                              mapping(bytes32 => address) public contractMap;
                              mapping(address => address) public rootToChildToken;
                              mapping(address => address) public childToRootToken;
                              mapping(address => bool) public proofValidatorContracts;
                              mapping(address => bool) public isERC721;
                          
                              enum Type {Invalid, ERC20, ERC721, Custom}
                              struct Predicate {
                                  Type _type;
                              }
                              mapping(address => Predicate) public predicates;
                          
                              event TokenMapped(address indexed rootToken, address indexed childToken);
                              event ProofValidatorAdded(address indexed validator, address indexed from);
                              event ProofValidatorRemoved(address indexed validator, address indexed from);
                              event PredicateAdded(address indexed predicate, address indexed from);
                              event PredicateRemoved(address indexed predicate, address indexed from);
                              event ContractMapUpdated(bytes32 indexed key, address indexed previousContract, address indexed newContract);
                          
                              constructor(address _governance) public Governable(_governance) {}
                          
                              function updateContractMap(bytes32 _key, address _address) external onlyGovernance {
                                  emit ContractMapUpdated(_key, contractMap[_key], _address);
                                  contractMap[_key] = _address;
                              }
                          
                              /**
                               * @dev Map root token to child token
                               * @param _rootToken Token address on the root chain
                               * @param _childToken Token address on the child chain
                               * @param _isERC721 Is the token being mapped ERC721
                               */
                              function mapToken(
                                  address _rootToken,
                                  address _childToken,
                                  bool _isERC721
                              ) external onlyGovernance {
                                  require(_rootToken != address(0x0) && _childToken != address(0x0), "INVALID_TOKEN_ADDRESS");
                                  rootToChildToken[_rootToken] = _childToken;
                                  childToRootToken[_childToken] = _rootToken;
                                  isERC721[_rootToken] = _isERC721;
                                  IWithdrawManager(contractMap[WITHDRAW_MANAGER]).createExitQueue(_rootToken);
                                  emit TokenMapped(_rootToken, _childToken);
                              }
                          
                              function addErc20Predicate(address predicate) public onlyGovernance {
                                  require(predicate != address(0x0), "Can not add null address as predicate");
                                  erc20Predicate = predicate;
                                  addPredicate(predicate, Type.ERC20);
                              }
                          
                              function addErc721Predicate(address predicate) public onlyGovernance {
                                  erc721Predicate = predicate;
                                  addPredicate(predicate, Type.ERC721);
                              }
                          
                              function addPredicate(address predicate, Type _type) public onlyGovernance {
                                  require(predicates[predicate]._type == Type.Invalid, "Predicate already added");
                                  predicates[predicate]._type = _type;
                                  emit PredicateAdded(predicate, msg.sender);
                              }
                          
                              function removePredicate(address predicate) public onlyGovernance {
                                  require(predicates[predicate]._type != Type.Invalid, "Predicate does not exist");
                                  delete predicates[predicate];
                                  emit PredicateRemoved(predicate, msg.sender);
                              }
                          
                              function getValidatorShareAddress() public view returns (address) {
                                  return contractMap[VALIDATOR_SHARE];
                              }
                          
                              function getWethTokenAddress() public view returns (address) {
                                  return contractMap[WETH_TOKEN];
                              }
                          
                              function getDepositManagerAddress() public view returns (address) {
                                  return contractMap[DEPOSIT_MANAGER];
                              }
                          
                              function getStakeManagerAddress() public view returns (address) {
                                  return contractMap[STAKE_MANAGER];
                              }
                          
                              function getSlashingManagerAddress() public view returns (address) {
                                  return contractMap[SLASHING_MANAGER];
                              }
                          
                              function getWithdrawManagerAddress() public view returns (address) {
                                  return contractMap[WITHDRAW_MANAGER];
                              }
                          
                              function getChildChainAndStateSender() public view returns (address, address) {
                                  return (contractMap[CHILD_CHAIN], contractMap[STATE_SENDER]);
                              }
                          
                              function isTokenMapped(address _token) public view returns (bool) {
                                  return rootToChildToken[_token] != address(0x0);
                              }
                          
                              function isTokenMappedAndIsErc721(address _token) public view returns (bool) {
                                  require(isTokenMapped(_token), "TOKEN_NOT_MAPPED");
                                  return isERC721[_token];
                              }
                          
                              function isTokenMappedAndGetPredicate(address _token) public view returns (address) {
                                  if (isTokenMappedAndIsErc721(_token)) {
                                      return erc721Predicate;
                                  }
                                  return erc20Predicate;
                              }
                          
                              function isChildTokenErc721(address childToken) public view returns (bool) {
                                  address rootToken = childToRootToken[childToken];
                                  require(rootToken != address(0x0), "Child token is not mapped");
                                  return isERC721[rootToken];
                              }
                          }
                          
                          // File: openzeppelin-solidity/contracts/math/SafeMath.sol
                          
                          pragma solidity ^0.5.2;
                          
                          /**
                           * @title SafeMath
                           * @dev Unsigned math operations with safety checks that revert on error
                           */
                          library SafeMath {
                              /**
                               * @dev Multiplies two unsigned integers, reverts on overflow.
                               */
                              function mul(uint256 a, uint256 b) internal pure returns (uint256) {
                                  // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
                                  // benefit is lost if 'b' is also tested.
                                  // See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522
                                  if (a == 0) {
                                      return 0;
                                  }
                          
                                  uint256 c = a * b;
                                  require(c / a == b);
                          
                                  return c;
                              }
                          
                              /**
                               * @dev Integer division of two unsigned integers truncating the quotient, reverts on division by zero.
                               */
                              function div(uint256 a, uint256 b) internal pure returns (uint256) {
                                  // Solidity only automatically asserts when dividing by 0
                                  require(b > 0);
                                  uint256 c = a / b;
                                  // assert(a == b * c + a % b); // There is no case in which this doesn't hold
                          
                                  return c;
                              }
                          
                              /**
                               * @dev Subtracts two unsigned integers, reverts on overflow (i.e. if subtrahend is greater than minuend).
                               */
                              function sub(uint256 a, uint256 b) internal pure returns (uint256) {
                                  require(b <= a);
                                  uint256 c = a - b;
                          
                                  return c;
                              }
                          
                              /**
                               * @dev Adds two unsigned integers, reverts on overflow.
                               */
                              function add(uint256 a, uint256 b) internal pure returns (uint256) {
                                  uint256 c = a + b;
                                  require(c >= a);
                          
                                  return c;
                              }
                          
                              /**
                               * @dev Divides two unsigned integers and returns the remainder (unsigned integer modulo),
                               * reverts when dividing by zero.
                               */
                              function mod(uint256 a, uint256 b) internal pure returns (uint256) {
                                  require(b != 0);
                                  return a % b;
                              }
                          }
                          
                          // File: openzeppelin-solidity/contracts/ownership/Ownable.sol
                          
                          pragma solidity ^0.5.2;
                          
                          /**
                           * @title Ownable
                           * @dev The Ownable contract has an owner address, and provides basic authorization control
                           * functions, this simplifies the implementation of "user permissions".
                           */
                          contract Ownable {
                              address private _owner;
                          
                              event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
                          
                              /**
                               * @dev The Ownable constructor sets the original `owner` of the contract to the sender
                               * account.
                               */
                              constructor () internal {
                                  _owner = msg.sender;
                                  emit OwnershipTransferred(address(0), _owner);
                              }
                          
                              /**
                               * @return the address of the owner.
                               */
                              function owner() public view returns (address) {
                                  return _owner;
                              }
                          
                              /**
                               * @dev Throws if called by any account other than the owner.
                               */
                              modifier onlyOwner() {
                                  require(isOwner());
                                  _;
                              }
                          
                              /**
                               * @return true if `msg.sender` is the owner of the contract.
                               */
                              function isOwner() public view returns (bool) {
                                  return msg.sender == _owner;
                              }
                          
                              /**
                               * @dev Allows the current owner to relinquish control of the contract.
                               * It will not be possible to call the functions with the `onlyOwner`
                               * modifier anymore.
                               * @notice Renouncing ownership will leave the contract without an owner,
                               * thereby removing any functionality that is only available to the owner.
                               */
                              function renounceOwnership() public onlyOwner {
                                  emit OwnershipTransferred(_owner, address(0));
                                  _owner = address(0);
                              }
                          
                              /**
                               * @dev Allows the current owner to transfer control of the contract to a newOwner.
                               * @param newOwner The address to transfer ownership to.
                               */
                              function transferOwnership(address newOwner) public onlyOwner {
                                  _transferOwnership(newOwner);
                              }
                          
                              /**
                               * @dev Transfers control of the contract to a newOwner.
                               * @param newOwner The address to transfer ownership to.
                               */
                              function _transferOwnership(address newOwner) internal {
                                  require(newOwner != address(0));
                                  emit OwnershipTransferred(_owner, newOwner);
                                  _owner = newOwner;
                              }
                          }
                          
                          // File: contracts/common/lib/BytesLib.sol
                          
                          pragma solidity ^0.5.2;
                          
                          
                          library BytesLib {
                              function concat(bytes memory _preBytes, bytes memory _postBytes)
                                  internal
                                  pure
                                  returns (bytes memory)
                              {
                                  bytes memory tempBytes;
                                  assembly {
                                      // Get a location of some free memory and store it in tempBytes as
                                      // Solidity does for memory variables.
                                      tempBytes := mload(0x40)
                          
                                      // Store the length of the first bytes array at the beginning of
                                      // the memory for tempBytes.
                                      let length := mload(_preBytes)
                                      mstore(tempBytes, length)
                          
                                      // Maintain a memory counter for the current write location in the
                                      // temp bytes array by adding the 32 bytes for the array length to
                                      // the starting location.
                                      let mc := add(tempBytes, 0x20)
                                      // Stop copying when the memory counter reaches the length of the
                                      // first bytes array.
                                      let end := add(mc, length)
                          
                                      for {
                                          // Initialize a copy counter to the start of the _preBytes data,
                                          // 32 bytes into its memory.
                                          let cc := add(_preBytes, 0x20)
                                      } lt(mc, end) {
                                          // Increase both counters by 32 bytes each iteration.
                                          mc := add(mc, 0x20)
                                          cc := add(cc, 0x20)
                                      } {
                                          // Write the _preBytes data into the tempBytes memory 32 bytes
                                          // at a time.
                                          mstore(mc, mload(cc))
                                      }
                          
                                      // Add the length of _postBytes to the current length of tempBytes
                                      // and store it as the new length in the first 32 bytes of the
                                      // tempBytes memory.
                                      length := mload(_postBytes)
                                      mstore(tempBytes, add(length, mload(tempBytes)))
                          
                                      // Move the memory counter back from a multiple of 0x20 to the
                                      // actual end of the _preBytes data.
                                      mc := end
                                      // Stop copying when the memory counter reaches the new combined
                                      // length of the arrays.
                                      end := add(mc, length)
                          
                                      for {
                                          let cc := add(_postBytes, 0x20)
                                      } lt(mc, end) {
                                          mc := add(mc, 0x20)
                                          cc := add(cc, 0x20)
                                      } {
                                          mstore(mc, mload(cc))
                                      }
                          
                                      // Update the free-memory pointer by padding our last write location
                                      // to 32 bytes: add 31 bytes to the end of tempBytes to move to the
                                      // next 32 byte block, then round down to the nearest multiple of
                                      // 32. If the sum of the length of the two arrays is zero then add
                                      // one before rounding down to leave a blank 32 bytes (the length block with 0).
                                      mstore(
                                          0x40,
                                          and(
                                              add(add(end, iszero(add(length, mload(_preBytes)))), 31),
                                              not(31) // Round down to the nearest 32 bytes.
                                          )
                                      )
                                  }
                                  return tempBytes;
                              }
                          
                              function slice(bytes memory _bytes, uint256 _start, uint256 _length)
                                  internal
                                  pure
                                  returns (bytes memory)
                              {
                                  require(_bytes.length >= (_start + _length));
                                  bytes memory tempBytes;
                                  assembly {
                                      switch iszero(_length)
                                          case 0 {
                                              // Get a location of some free memory and store it in tempBytes as
                                              // Solidity does for memory variables.
                                              tempBytes := mload(0x40)
                          
                                              // The first word of the slice result is potentially a partial
                                              // word read from the original array. To read it, we calculate
                                              // the length of that partial word and start copying that many
                                              // bytes into the array. The first word we copy will start with
                                              // data we don't care about, but the last `lengthmod` bytes will
                                              // land at the beginning of the contents of the new array. When
                                              // we're done copying, we overwrite the full first word with
                                              // the actual length of the slice.
                                              let lengthmod := and(_length, 31)
                          
                                              // The multiplication in the next line is necessary
                                              // because when slicing multiples of 32 bytes (lengthmod == 0)
                                              // the following copy loop was copying the origin's length
                                              // and then ending prematurely not copying everything it should.
                                              let mc := add(
                                                  add(tempBytes, lengthmod),
                                                  mul(0x20, iszero(lengthmod))
                                              )
                                              let end := add(mc, _length)
                          
                                              for {
                                                  // The multiplication in the next line has the same exact purpose
                                                  // as the one above.
                                                  let cc := add(
                                                      add(
                                                          add(_bytes, lengthmod),
                                                          mul(0x20, iszero(lengthmod))
                                                      ),
                                                      _start
                                                  )
                                              } lt(mc, end) {
                                                  mc := add(mc, 0x20)
                                                  cc := add(cc, 0x20)
                                              } {
                                                  mstore(mc, mload(cc))
                                              }
                          
                                              mstore(tempBytes, _length)
                          
                                              //update free-memory pointer
                                              //allocating the array padded to 32 bytes like the compiler does now
                                              mstore(0x40, and(add(mc, 31), not(31)))
                                          }
                                          //if we want a zero-length slice let's just return a zero-length array
                                          default {
                                              tempBytes := mload(0x40)
                                              mstore(0x40, add(tempBytes, 0x20))
                                          }
                                  }
                          
                                  return tempBytes;
                              }
                          
                              // Pad a bytes array to 32 bytes
                              function leftPad(bytes memory _bytes) internal pure returns (bytes memory) {
                                  // may underflow if bytes.length < 32. Hence using SafeMath.sub
                                  bytes memory newBytes = new bytes(SafeMath.sub(32, _bytes.length));
                                  return concat(newBytes, _bytes);
                              }
                          
                              function toBytes32(bytes memory b) internal pure returns (bytes32) {
                                  require(b.length >= 32, "Bytes array should atleast be 32 bytes");
                                  bytes32 out;
                                  for (uint256 i = 0; i < 32; i++) {
                                      out |= bytes32(b[i] & 0xFF) >> (i * 8);
                                  }
                                  return out;
                              }
                          
                              function toBytes4(bytes memory b) internal pure returns (bytes4 result) {
                                  assembly {
                                      result := mload(add(b, 32))
                                  }
                              }
                          
                              function fromBytes32(bytes32 x) internal pure returns (bytes memory) {
                                  bytes memory b = new bytes(32);
                                  for (uint256 i = 0; i < 32; i++) {
                                      b[i] = bytes1(uint8(uint256(x) / (2**(8 * (31 - i)))));
                                  }
                                  return b;
                              }
                          
                              function fromUint(uint256 _num) internal pure returns (bytes memory _ret) {
                                  _ret = new bytes(32);
                                  assembly {
                                      mstore(add(_ret, 32), _num)
                                  }
                              }
                          
                              function toUint(bytes memory _bytes, uint256 _start)
                                  internal
                                  pure
                                  returns (uint256)
                              {
                                  require(_bytes.length >= (_start + 32));
                                  uint256 tempUint;
                                  assembly {
                                      tempUint := mload(add(add(_bytes, 0x20), _start))
                                  }
                                  return tempUint;
                              }
                          
                              function toAddress(bytes memory _bytes, uint256 _start)
                                  internal
                                  pure
                                  returns (address)
                              {
                                  require(_bytes.length >= (_start + 20));
                                  address tempAddress;
                                  assembly {
                                      tempAddress := div(
                                          mload(add(add(_bytes, 0x20), _start)),
                                          0x1000000000000000000000000
                                      )
                                  }
                          
                                  return tempAddress;
                              }
                          }
                          
                          // File: contracts/common/lib/ECVerify.sol
                          
                          pragma solidity ^0.5.2;
                          
                          
                          library ECVerify {
                              function ecrecovery(bytes32 hash, bytes memory sig)
                                  public
                                  pure
                                  returns (address)
                              {
                                  bytes32 r;
                                  bytes32 s;
                                  uint8 v;
                          
                                  if (sig.length != 65) {
                                      return address(0x0);
                                  }
                          
                                  assembly {
                                      r := mload(add(sig, 32))
                                      s := mload(add(sig, 64))
                                      v := and(mload(add(sig, 65)), 255)
                                  }
                          
                                  // https://github.com/ethereum/go-ethereum/issues/2053
                                  if (v < 27) {
                                      v += 27;
                                  }
                          
                                  if (v != 27 && v != 28) {
                                      return address(0x0);
                                  }
                          
                                  // get address out of hash and signature
                                  address result = ecrecover(hash, v, r, s);
                          
                                  // ecrecover returns zero on error
                                  require(result != address(0x0));
                          
                                  return result;
                              }
                          
                              function ecrecovery(bytes32 hash, uint8 v, bytes32 r, bytes32 s)
                                  public
                                  pure
                                  returns (address)
                              {
                                  // get address out of hash and signature
                                  address result = ecrecover(hash, v, r, s);
                          
                                  // ecrecover returns zero on error
                                  require(result != address(0x0), "signature verification failed");
                          
                                  return result;
                              }
                          
                              function ecverify(bytes32 hash, bytes memory sig, address signer)
                                  public
                                  pure
                                  returns (bool)
                              {
                                  return signer == ecrecovery(hash, sig);
                              }
                          }
                          
                          // File: contracts/staking/StakingInfo.sol
                          
                          pragma solidity ^0.5.2;
                          
                          
                          
                          
                          
                          
                          
                          // dummy interface to avoid cyclic dependency
                          contract IStakeManagerLocal {
                              enum Status {Inactive, Active, Locked, Unstaked}
                          
                              struct Validator {
                                  uint256 amount;
                                  uint256 reward;
                                  uint256 activationEpoch;
                                  uint256 deactivationEpoch;
                                  uint256 jailTime;
                                  address signer;
                                  address contractAddress;
                                  Status status;
                              }
                          
                              mapping(uint256 => Validator) public validators;
                              bytes32 public accountStateRoot;
                              uint256 public activeAmount; // delegation amount from validator contract
                              uint256 public validatorRewards;
                          
                              function currentValidatorSetTotalStake() public view returns (uint256);
                          
                              // signer to Validator mapping
                              function signerToValidator(address validatorAddress)
                                  public
                                  view
                                  returns (uint256);
                          
                              function isValidator(uint256 validatorId) public view returns (bool);
                          }
                          
                          
                          contract StakingInfo is Ownable {
                              using SafeMath for uint256;
                              mapping(uint256 => uint256) public validatorNonce;
                          
                              /// @dev Emitted when validator stakes in '_stakeFor()' in StakeManager.
                              /// @param signer validator address.
                              /// @param validatorId unique integer to identify a validator.
                              /// @param nonce to synchronize the events in heimdal.
                              /// @param activationEpoch validator's first epoch as proposer.
                              /// @param amount staking amount.
                              /// @param total total staking amount.
                              /// @param signerPubkey public key of the validator
                              event Staked(
                                  address indexed signer,
                                  uint256 indexed validatorId,
                                  uint256 nonce,
                                  uint256 indexed activationEpoch,
                                  uint256 amount,
                                  uint256 total,
                                  bytes signerPubkey
                              );
                          
                              /// @dev Emitted when validator unstakes in 'unstakeClaim()'
                              /// @param user address of the validator.
                              /// @param validatorId unique integer to identify a validator.
                              /// @param amount staking amount.
                              /// @param total total staking amount.
                              event Unstaked(
                                  address indexed user,
                                  uint256 indexed validatorId,
                                  uint256 amount,
                                  uint256 total
                              );
                          
                              /// @dev Emitted when validator unstakes in '_unstake()'.
                              /// @param user address of the validator.
                              /// @param validatorId unique integer to identify a validator.
                              /// @param nonce to synchronize the events in heimdal.
                              /// @param deactivationEpoch last epoch for validator.
                              /// @param amount staking amount.
                              event UnstakeInit(
                                  address indexed user,
                                  uint256 indexed validatorId,
                                  uint256 nonce,
                                  uint256 deactivationEpoch,
                                  uint256 indexed amount
                              );
                          
                              /// @dev Emitted when the validator public key is updated in 'updateSigner()'.
                              /// @param validatorId unique integer to identify a validator.
                              /// @param nonce to synchronize the events in heimdal.
                              /// @param oldSigner old address of the validator.
                              /// @param newSigner new address of the validator.
                              /// @param signerPubkey public key of the validator.
                              event SignerChange(
                                  uint256 indexed validatorId,
                                  uint256 nonce,
                                  address indexed oldSigner,
                                  address indexed newSigner,
                                  bytes signerPubkey
                              );
                              event Restaked(uint256 indexed validatorId, uint256 amount, uint256 total);
                              event Jailed(
                                  uint256 indexed validatorId,
                                  uint256 indexed exitEpoch,
                                  address indexed signer
                              );
                              event UnJailed(uint256 indexed validatorId, address indexed signer);
                              event Slashed(uint256 indexed nonce, uint256 indexed amount);
                              event ThresholdChange(uint256 newThreshold, uint256 oldThreshold);
                              event DynastyValueChange(uint256 newDynasty, uint256 oldDynasty);
                              event ProposerBonusChange(
                                  uint256 newProposerBonus,
                                  uint256 oldProposerBonus
                              );
                          
                              event RewardUpdate(uint256 newReward, uint256 oldReward);
                          
                              /// @dev Emitted when validator confirms the auction bid and at the time of restaking in confirmAuctionBid() and restake().
                              /// @param validatorId unique integer to identify a validator.
                              /// @param nonce to synchronize the events in heimdal.
                              /// @param newAmount the updated stake amount.
                              event StakeUpdate(
                                  uint256 indexed validatorId,
                                  uint256 indexed nonce,
                                  uint256 indexed newAmount
                              );
                              event ClaimRewards(
                                  uint256 indexed validatorId,
                                  uint256 indexed amount,
                                  uint256 indexed totalAmount
                              );
                              event StartAuction(
                                  uint256 indexed validatorId,
                                  uint256 indexed amount,
                                  uint256 indexed auctionAmount
                              );
                              event ConfirmAuction(
                                  uint256 indexed newValidatorId,
                                  uint256 indexed oldValidatorId,
                                  uint256 indexed amount
                              );
                              event TopUpFee(address indexed user, uint256 indexed fee);
                              event ClaimFee(address indexed user, uint256 indexed fee);
                              // Delegator events
                              event ShareMinted(
                                  uint256 indexed validatorId,
                                  address indexed user,
                                  uint256 indexed amount,
                                  uint256 tokens
                              );
                              event ShareBurned(
                                  uint256 indexed validatorId,
                                  address indexed user,
                                  uint256 indexed amount,
                                  uint256 tokens
                              );
                              event DelegatorClaimedRewards(
                                  uint256 indexed validatorId,
                                  address indexed user,
                                  uint256 indexed rewards
                              );
                              event DelegatorRestaked(
                                  uint256 indexed validatorId,
                                  address indexed user,
                                  uint256 indexed totalStaked
                              );
                              event DelegatorUnstaked(
                                  uint256 indexed validatorId,
                                  address indexed user,
                                  uint256 amount
                              );
                              event UpdateCommissionRate(
                                  uint256 indexed validatorId,
                                  uint256 indexed newCommissionRate,
                                  uint256 indexed oldCommissionRate
                              );
                          
                              Registry public registry;
                          
                              modifier onlyValidatorContract(uint256 validatorId) {
                                  address _contract;
                                  (, , , , , , _contract, ) = IStakeManagerLocal(
                                      registry.getStakeManagerAddress()
                                  )
                                      .validators(validatorId);
                                  require(_contract == msg.sender,
                                  "Invalid sender, not validator");
                                  _;
                              }
                          
                              modifier StakeManagerOrValidatorContract(uint256 validatorId) {
                                  address _contract;
                                  address _stakeManager = registry.getStakeManagerAddress();
                                  (, , , , , , _contract, ) = IStakeManagerLocal(_stakeManager).validators(
                                      validatorId
                                  );
                                  require(_contract == msg.sender || _stakeManager == msg.sender,
                                  "Invalid sender, not stake manager or validator contract");
                                  _;
                              }
                          
                              modifier onlyStakeManager() {
                                  require(registry.getStakeManagerAddress() == msg.sender,
                                  "Invalid sender, not stake manager");
                                  _;
                              }
                              modifier onlySlashingManager() {
                                  require(registry.getSlashingManagerAddress() == msg.sender,
                                  "Invalid sender, not slashing manager");
                                  _;
                              }
                          
                              constructor(address _registry) public {
                                  registry = Registry(_registry);
                              }
                          
                              function updateNonce(
                                  uint256[] calldata validatorIds,
                                  uint256[] calldata nonces
                              ) external onlyOwner {
                                  require(validatorIds.length == nonces.length, "args length mismatch");
                          
                                  for (uint256 i = 0; i < validatorIds.length; ++i) {
                                      validatorNonce[validatorIds[i]] = nonces[i];
                                  }
                              } 
                          
                              function logStaked(
                                  address signer,
                                  bytes memory signerPubkey,
                                  uint256 validatorId,
                                  uint256 activationEpoch,
                                  uint256 amount,
                                  uint256 total
                              ) public onlyStakeManager {
                                  validatorNonce[validatorId] = validatorNonce[validatorId].add(1);
                                  emit Staked(
                                      signer,
                                      validatorId,
                                      validatorNonce[validatorId],
                                      activationEpoch,
                                      amount,
                                      total,
                                      signerPubkey
                                  );
                              }
                          
                              function logUnstaked(
                                  address user,
                                  uint256 validatorId,
                                  uint256 amount,
                                  uint256 total
                              ) public onlyStakeManager {
                                  emit Unstaked(user, validatorId, amount, total);
                              }
                          
                              function logUnstakeInit(
                                  address user,
                                  uint256 validatorId,
                                  uint256 deactivationEpoch,
                                  uint256 amount
                              ) public onlyStakeManager {
                                  validatorNonce[validatorId] = validatorNonce[validatorId].add(1);
                                  emit UnstakeInit(
                                      user,
                                      validatorId,
                                      validatorNonce[validatorId],
                                      deactivationEpoch,
                                      amount
                                  );
                              }
                          
                              function logSignerChange(
                                  uint256 validatorId,
                                  address oldSigner,
                                  address newSigner,
                                  bytes memory signerPubkey
                              ) public onlyStakeManager {
                                  validatorNonce[validatorId] = validatorNonce[validatorId].add(1);
                                  emit SignerChange(
                                      validatorId,
                                      validatorNonce[validatorId],
                                      oldSigner,
                                      newSigner,
                                      signerPubkey
                                  );
                              }
                          
                              function logRestaked(uint256 validatorId, uint256 amount, uint256 total)
                                  public
                                  onlyStakeManager
                              {
                                  emit Restaked(validatorId, amount, total);
                              }
                          
                              function logJailed(uint256 validatorId, uint256 exitEpoch, address signer)
                                  public
                                  onlyStakeManager
                              {
                                  emit Jailed(validatorId, exitEpoch, signer);
                              }
                          
                              function logUnjailed(uint256 validatorId, address signer)
                                  public
                                  onlyStakeManager
                              {
                                  emit UnJailed(validatorId, signer);
                              }
                          
                              function logSlashed(uint256 nonce, uint256 amount)
                                  public
                                  onlySlashingManager
                              {
                                  emit Slashed(nonce, amount);
                              }
                          
                              function logThresholdChange(uint256 newThreshold, uint256 oldThreshold)
                                  public
                                  onlyStakeManager
                              {
                                  emit ThresholdChange(newThreshold, oldThreshold);
                              }
                          
                              function logDynastyValueChange(uint256 newDynasty, uint256 oldDynasty)
                                  public
                                  onlyStakeManager
                              {
                                  emit DynastyValueChange(newDynasty, oldDynasty);
                              }
                          
                              function logProposerBonusChange(
                                  uint256 newProposerBonus,
                                  uint256 oldProposerBonus
                              ) public onlyStakeManager {
                                  emit ProposerBonusChange(newProposerBonus, oldProposerBonus);
                              }
                          
                              function logRewardUpdate(uint256 newReward, uint256 oldReward)
                                  public
                                  onlyStakeManager
                              {
                                  emit RewardUpdate(newReward, oldReward);
                              }
                          
                              function logStakeUpdate(uint256 validatorId)
                                  public
                                  StakeManagerOrValidatorContract(validatorId)
                              {
                                  validatorNonce[validatorId] = validatorNonce[validatorId].add(1);
                                  emit StakeUpdate(
                                      validatorId,
                                      validatorNonce[validatorId],
                                      totalValidatorStake(validatorId)
                                  );
                              }
                          
                              function logClaimRewards(
                                  uint256 validatorId,
                                  uint256 amount,
                                  uint256 totalAmount
                              ) public onlyStakeManager {
                                  emit ClaimRewards(validatorId, amount, totalAmount);
                              }
                          
                              function logStartAuction(
                                  uint256 validatorId,
                                  uint256 amount,
                                  uint256 auctionAmount
                              ) public onlyStakeManager {
                                  emit StartAuction(validatorId, amount, auctionAmount);
                              }
                          
                              function logConfirmAuction(
                                  uint256 newValidatorId,
                                  uint256 oldValidatorId,
                                  uint256 amount
                              ) public onlyStakeManager {
                                  emit ConfirmAuction(newValidatorId, oldValidatorId, amount);
                              }
                          
                              function logTopUpFee(address user, uint256 fee) public onlyStakeManager {
                                  emit TopUpFee(user, fee);
                              }
                          
                              function logClaimFee(address user, uint256 fee) public onlyStakeManager {
                                  emit ClaimFee(user, fee);
                              }
                          
                              function getStakerDetails(uint256 validatorId)
                                  public
                                  view
                                  returns (
                                      uint256 amount,
                                      uint256 reward,
                                      uint256 activationEpoch,
                                      uint256 deactivationEpoch,
                                      address signer,
                                      uint256 _status
                                  )
                              {
                                  IStakeManagerLocal stakeManager = IStakeManagerLocal(
                                      registry.getStakeManagerAddress()
                                  );
                                  address _contract;
                                  IStakeManagerLocal.Status status;
                                  (
                                      amount,
                                      reward,
                                      activationEpoch,
                                      deactivationEpoch,
                                      ,
                                      signer,
                                      _contract,
                                      status
                                  ) = stakeManager.validators(validatorId);
                                  _status = uint256(status);
                                  if (_contract != address(0x0)) {
                                      reward += IStakeManagerLocal(_contract).validatorRewards();
                                  }
                              }
                          
                              function totalValidatorStake(uint256 validatorId)
                                  public
                                  view
                                  returns (uint256 validatorStake)
                              {
                                  address contractAddress;
                                  (validatorStake, , , , , , contractAddress, ) = IStakeManagerLocal(
                                      registry.getStakeManagerAddress()
                                  )
                                      .validators(validatorId);
                                  if (contractAddress != address(0x0)) {
                                      validatorStake += IStakeManagerLocal(contractAddress).activeAmount();
                                  }
                              }
                          
                              function getAccountStateRoot()
                                  public
                                  view
                                  returns (bytes32 accountStateRoot)
                              {
                                  accountStateRoot = IStakeManagerLocal(registry.getStakeManagerAddress())
                                      .accountStateRoot();
                              }
                          
                              function getValidatorContractAddress(uint256 validatorId)
                                  public
                                  view
                                  returns (address ValidatorContract)
                              {
                                  (, , , , , , ValidatorContract, ) = IStakeManagerLocal(
                                      registry.getStakeManagerAddress()
                                  )
                                      .validators(validatorId);
                              }
                          
                              // validator Share contract logging func
                              function logShareMinted(
                                  uint256 validatorId,
                                  address user,
                                  uint256 amount,
                                  uint256 tokens
                              ) public onlyValidatorContract(validatorId) {
                                  emit ShareMinted(validatorId, user, amount, tokens);
                              }
                          
                              function logShareBurned(
                                  uint256 validatorId,
                                  address user,
                                  uint256 amount,
                                  uint256 tokens
                              ) public onlyValidatorContract(validatorId) {
                                  emit ShareBurned(validatorId, user, amount, tokens);
                              }
                          
                              function logDelegatorClaimRewards(
                                  uint256 validatorId,
                                  address user,
                                  uint256 rewards
                              ) public onlyValidatorContract(validatorId) {
                                  emit DelegatorClaimedRewards(validatorId, user, rewards);
                              }
                          
                              function logDelegatorRestaked(
                                  uint256 validatorId,
                                  address user,
                                  uint256 totalStaked
                              ) public onlyValidatorContract(validatorId) {
                                  emit DelegatorRestaked(validatorId, user, totalStaked);
                              }
                          
                              function logDelegatorUnstaked(uint256 validatorId, address user, uint256 amount)
                                  public
                                  onlyValidatorContract(validatorId)
                              {
                                  emit DelegatorUnstaked(validatorId, user, amount);
                              }
                          
                              function logUpdateCommissionRate(
                                  uint256 validatorId,
                                  uint256 newCommissionRate,
                                  uint256 oldCommissionRate
                              ) public onlyValidatorContract(validatorId) {
                                  emit UpdateCommissionRate(
                                      validatorId,
                                      newCommissionRate,
                                      oldCommissionRate
                                  );
                              }
                          }

                          File 3 of 6: Registry
                          /**
                          Matic network contracts
                          */
                          
                          pragma solidity ^0.5.2;
                          
                          
                          interface IGovernance {
                              function update(address target, bytes calldata data) external;
                          }
                          
                          contract Governable {
                              IGovernance public governance;
                          
                              constructor(address _governance) public {
                                  governance = IGovernance(_governance);
                              }
                          
                              modifier onlyGovernance() {
                                  require(
                                      msg.sender == address(governance),
                                      "Only governance contract is authorized"
                                  );
                                  _;
                              }
                          }
                          
                          contract IWithdrawManager {
                              function createExitQueue(address token) external;
                          
                              function verifyInclusion(
                                  bytes calldata data,
                                  uint8 offset,
                                  bool verifyTxInclusion
                              ) external view returns (uint256 age);
                          
                              function addExitToQueue(
                                  address exitor,
                                  address childToken,
                                  address rootToken,
                                  uint256 exitAmountOrTokenId,
                                  bytes32 txHash,
                                  bool isRegularExit,
                                  uint256 priority
                              ) external;
                          
                              function addInput(
                                  uint256 exitId,
                                  uint256 age,
                                  address utxoOwner,
                                  address token
                              ) external;
                          
                              function challengeExit(
                                  uint256 exitId,
                                  uint256 inputId,
                                  bytes calldata challengeData,
                                  address adjudicatorPredicate
                              ) external;
                          }
                          
                          contract Registry is Governable {
                              // @todo hardcode constants
                              bytes32 private constant WETH_TOKEN = keccak256("wethToken");
                              bytes32 private constant DEPOSIT_MANAGER = keccak256("depositManager");
                              bytes32 private constant STAKE_MANAGER = keccak256("stakeManager");
                              bytes32 private constant VALIDATOR_SHARE = keccak256("validatorShare");
                              bytes32 private constant WITHDRAW_MANAGER = keccak256("withdrawManager");
                              bytes32 private constant CHILD_CHAIN = keccak256("childChain");
                              bytes32 private constant STATE_SENDER = keccak256("stateSender");
                              bytes32 private constant SLASHING_MANAGER = keccak256("slashingManager");
                          
                              address public erc20Predicate;
                              address public erc721Predicate;
                          
                              mapping(bytes32 => address) public contractMap;
                              mapping(address => address) public rootToChildToken;
                              mapping(address => address) public childToRootToken;
                              mapping(address => bool) public proofValidatorContracts;
                              mapping(address => bool) public isERC721;
                          
                              enum Type {Invalid, ERC20, ERC721, Custom}
                              struct Predicate {
                                  Type _type;
                              }
                              mapping(address => Predicate) public predicates;
                          
                              event TokenMapped(address indexed rootToken, address indexed childToken);
                              event ProofValidatorAdded(address indexed validator, address indexed from);
                              event ProofValidatorRemoved(address indexed validator, address indexed from);
                              event PredicateAdded(address indexed predicate, address indexed from);
                              event PredicateRemoved(address indexed predicate, address indexed from);
                              event ContractMapUpdated(bytes32 indexed key, address indexed previousContract, address indexed newContract);
                          
                              constructor(address _governance) public Governable(_governance) {}
                          
                              function updateContractMap(bytes32 _key, address _address) external onlyGovernance {
                                  emit ContractMapUpdated(_key, contractMap[_key], _address);
                                  contractMap[_key] = _address;
                              }
                          
                              /**
                               * @dev Map root token to child token
                               * @param _rootToken Token address on the root chain
                               * @param _childToken Token address on the child chain
                               * @param _isERC721 Is the token being mapped ERC721
                               */
                              function mapToken(
                                  address _rootToken,
                                  address _childToken,
                                  bool _isERC721
                              ) external onlyGovernance {
                                  require(_rootToken != address(0x0) && _childToken != address(0x0), "INVALID_TOKEN_ADDRESS");
                                  rootToChildToken[_rootToken] = _childToken;
                                  childToRootToken[_childToken] = _rootToken;
                                  isERC721[_rootToken] = _isERC721;
                                  IWithdrawManager(contractMap[WITHDRAW_MANAGER]).createExitQueue(_rootToken);
                                  emit TokenMapped(_rootToken, _childToken);
                              }
                          
                              function addErc20Predicate(address predicate) public onlyGovernance {
                                  require(predicate != address(0x0), "Can not add null address as predicate");
                                  erc20Predicate = predicate;
                                  addPredicate(predicate, Type.ERC20);
                              }
                          
                              function addErc721Predicate(address predicate) public onlyGovernance {
                                  erc721Predicate = predicate;
                                  addPredicate(predicate, Type.ERC721);
                              }
                          
                              function addPredicate(address predicate, Type _type) public onlyGovernance {
                                  require(predicates[predicate]._type == Type.Invalid, "Predicate already added");
                                  predicates[predicate]._type = _type;
                                  emit PredicateAdded(predicate, msg.sender);
                              }
                          
                              function removePredicate(address predicate) public onlyGovernance {
                                  require(predicates[predicate]._type != Type.Invalid, "Predicate does not exist");
                                  delete predicates[predicate];
                                  emit PredicateRemoved(predicate, msg.sender);
                              }
                          
                              function getValidatorShareAddress() public view returns (address) {
                                  return contractMap[VALIDATOR_SHARE];
                              }
                          
                              function getWethTokenAddress() public view returns (address) {
                                  return contractMap[WETH_TOKEN];
                              }
                          
                              function getDepositManagerAddress() public view returns (address) {
                                  return contractMap[DEPOSIT_MANAGER];
                              }
                          
                              function getStakeManagerAddress() public view returns (address) {
                                  return contractMap[STAKE_MANAGER];
                              }
                          
                              function getSlashingManagerAddress() public view returns (address) {
                                  return contractMap[SLASHING_MANAGER];
                              }
                          
                              function getWithdrawManagerAddress() public view returns (address) {
                                  return contractMap[WITHDRAW_MANAGER];
                              }
                          
                              function getChildChainAndStateSender() public view returns (address, address) {
                                  return (contractMap[CHILD_CHAIN], contractMap[STATE_SENDER]);
                              }
                          
                              function isTokenMapped(address _token) public view returns (bool) {
                                  return rootToChildToken[_token] != address(0x0);
                              }
                          
                              function isTokenMappedAndIsErc721(address _token) public view returns (bool) {
                                  require(isTokenMapped(_token), "TOKEN_NOT_MAPPED");
                                  return isERC721[_token];
                              }
                          
                              function isTokenMappedAndGetPredicate(address _token) public view returns (address) {
                                  if (isTokenMappedAndIsErc721(_token)) {
                                      return erc721Predicate;
                                  }
                                  return erc20Predicate;
                              }
                          
                              function isChildTokenErc721(address childToken) public view returns (bool) {
                                  address rootToken = childToRootToken[childToken];
                                  require(rootToken != address(0x0), "Child token is not mapped");
                                  return isERC721[rootToken];
                              }
                          }

                          File 4 of 6: ValidatorShare
                          pragma solidity 0.5.17;
                          import {Registry} from "../../common/Registry.sol";
                          import {ERC20NonTradable} from "../../common/tokens/ERC20NonTradable.sol";
                          import {ERC20} from "openzeppelin-solidity/contracts/token/ERC20/ERC20.sol";
                          import {StakingInfo} from "./../StakingInfo.sol";
                          import {EventsHub} from "./../EventsHub.sol";
                          import {OwnableLockable} from "../../common/mixin/OwnableLockable.sol";
                          import {IStakeManager} from "../stakeManager/IStakeManager.sol";
                          import {IValidatorShare} from "./IValidatorShare.sol";
                          import {Initializable} from "../../common/mixin/Initializable.sol";
                          import {IERC20Permit} from "./../../common/misc/IERC20Permit.sol";
                          contract ValidatorShare is IValidatorShare, ERC20NonTradable, OwnableLockable, Initializable {
                              struct DelegatorUnbond {
                                  uint256 shares;
                                  uint256 withdrawEpoch;
                              }
                              uint256 constant EXCHANGE_RATE_PRECISION = 100;
                              // maximum matic possible, even if rate will be 1 and all matic will be staked in one go, it will result in 10 ^ 58 shares
                              uint256 constant EXCHANGE_RATE_HIGH_PRECISION = 10**29;
                              uint256 constant MAX_COMMISION_RATE = 100;
                              uint256 constant REWARD_PRECISION = 10**25;
                              StakingInfo public stakingLogger;
                              IStakeManager public stakeManager;
                              uint256 public validatorId;
                              uint256 public validatorRewards_deprecated;
                              uint256 public commissionRate_deprecated;
                              uint256 public lastCommissionUpdate_deprecated;
                              uint256 public minAmount;
                              uint256 public totalStake_deprecated;
                              uint256 public rewardPerShare;
                              uint256 public activeAmount;
                              bool public delegation;
                              uint256 public withdrawPool;
                              uint256 public withdrawShares;
                              mapping(address => uint256) amountStaked_deprecated; // deprecated, keep for foundation delegators
                              mapping(address => DelegatorUnbond) public unbonds;
                              mapping(address => uint256) public initalRewardPerShare;
                              mapping(address => uint256) public unbondNonces;
                              mapping(address => mapping(uint256 => DelegatorUnbond)) public unbonds_new;
                              EventsHub public eventsHub;
                              IERC20Permit public polToken;
                              constructor() public {
                                  _disableInitializer();
                              }
                              // onlyOwner will prevent this contract from initializing, since it's owner is going to be 0x0 address
                              function initialize(
                                  uint256 _validatorId,
                                  address _stakingLogger,
                                  address _stakeManager
                              ) external initializer {
                                  validatorId = _validatorId;
                                  stakingLogger = StakingInfo(_stakingLogger);
                                  stakeManager = IStakeManager(_stakeManager);
                                  _transferOwnership(_stakeManager);
                                  _getOrCacheEventsHub();
                                  minAmount = 10**18;
                                  delegation = true;
                              }
                              /**
                                  Public View Methods
                              */
                              function exchangeRate() public view returns (uint256) {
                                  uint256 totalShares = totalSupply();
                                  uint256 precision = _getRatePrecision();
                                  return totalShares == 0 ? precision : stakeManager.delegatedAmount(validatorId).mul(precision).div(totalShares);
                              }
                              function getTotalStake(address user) public view returns (uint256, uint256) {
                                  uint256 shares = balanceOf(user);
                                  uint256 rate = exchangeRate();
                                  if (shares == 0) {
                                      return (0, rate);
                                  }
                                  return (rate.mul(shares).div(_getRatePrecision()), rate);
                              }
                              function withdrawExchangeRate() public view returns (uint256) {
                                  uint256 precision = _getRatePrecision();
                                  if (validatorId < 8) {
                                      // fix of potentially broken withdrawals for future unbonding
                                      // foundation validators have no slashing enabled and thus we can return default exchange rate
                                      // because without slashing rate will stay constant
                                      return precision;
                                  }
                                  uint256 _withdrawShares = withdrawShares;
                                  return _withdrawShares == 0 ? precision : withdrawPool.mul(precision).div(_withdrawShares);
                              }
                              function getLiquidRewards(address user) public view returns (uint256) {
                                  return _calculateReward(user, getRewardPerShare());
                              }
                              function getRewardPerShare() public view returns (uint256) {
                                  return _calculateRewardPerShareWithRewards(stakeManager.delegatorsReward(validatorId));
                              }
                              /**
                                  Public Methods
                               */
                              function buyVoucher(uint256 _amount, uint256 _minSharesToMint) public returns (uint256 amountToDeposit) {
                                  return _buyVoucher(_amount, _minSharesToMint, false);
                              }
                              // @dev permit only available on pol token
                              // @dev txn fails if frontrun, use buyVoucher instead
                              function buyVoucherWithPermit(
                                  uint256 _amount,
                                  uint256 _minSharesToMint,
                                  uint256 deadline,
                                  uint8 v,
                                  bytes32 r,
                                  bytes32 s
                              ) public returns (uint256 amountToDeposit) {
                                  IERC20Permit _polToken = _getOrCachePOLToken();
                                  uint256 nonceBefore = _polToken.nonces(msg.sender);
                                  _polToken.permit(msg.sender, address(stakeManager), _amount, deadline, v, r, s);
                                  require(_polToken.nonces(msg.sender) == nonceBefore + 1, "Invalid permit");
                                  return _buyVoucher(_amount, _minSharesToMint, true); // invokes stakeManager to pull token from msg.sender
                              }
                              function buyVoucherPOL(uint256 _amount, uint256 _minSharesToMint) public returns (uint256 amountToDeposit) {
                                  return _buyVoucher(_amount, _minSharesToMint, true);
                              }
                              function _buyVoucher(uint256 _amount, uint256 _minSharesToMint, bool pol) internal returns (uint256 amountToDeposit) {
                                  _withdrawAndTransferReward(msg.sender, pol);
                                  amountToDeposit = _buyShares(_amount, _minSharesToMint, msg.sender);
                                  require(
                                      pol
                                          ? stakeManager.delegationDepositPOL(validatorId, amountToDeposit, msg.sender)
                                          : stakeManager.delegationDeposit(validatorId, amountToDeposit, msg.sender),
                                      "deposit failed"
                                  );
                                  return amountToDeposit;
                              }
                              function restake() public returns (uint256, uint256) {
                                  return _restake(false);
                              }
                              function restakePOL() public returns (uint256, uint256) {
                                  return _restake(true);
                              }
                              function _restake(bool pol) public returns (uint256, uint256) {
                                  address user = msg.sender;
                                  uint256 liquidReward = _withdrawReward(user);
                                  uint256 amountRestaked;
                                  require(liquidReward >= minAmount, "Too small rewards to restake");
                                  if (liquidReward != 0) {
                                      amountRestaked = _buyShares(liquidReward, 0, user);
                                      if (liquidReward > amountRestaked) {
                                          // return change to the user
                                          require(
                                              pol
                                                  ? stakeManager.transferFundsPOL(validatorId, liquidReward - amountRestaked, user)
                                                  : stakeManager.transferFunds(validatorId, liquidReward - amountRestaked, user),
                                              "Insufficent rewards"
                                          );
                                          stakingLogger.logDelegatorClaimRewards(validatorId, user, liquidReward - amountRestaked);
                                      }
                                      (uint256 totalStaked, ) = getTotalStake(user);
                                      stakingLogger.logDelegatorRestaked(validatorId, user, totalStaked);
                                  }
                                  
                                  return (amountRestaked, liquidReward);
                              }
                              function sellVoucher(uint256 claimAmount, uint256 maximumSharesToBurn) public {
                                  __sellVoucher(claimAmount, maximumSharesToBurn, false);
                              }
                              function sellVoucherPOL(uint256 claimAmount, uint256 maximumSharesToBurn) public {
                                  __sellVoucher(claimAmount, maximumSharesToBurn, true);
                              }
                              function __sellVoucher(uint256 claimAmount, uint256 maximumSharesToBurn, bool pol) internal {
                                  (uint256 shares, uint256 _withdrawPoolShare) = _sellVoucher(claimAmount, maximumSharesToBurn, pol);
                                  DelegatorUnbond memory unbond = unbonds[msg.sender];
                                  unbond.shares = unbond.shares.add(_withdrawPoolShare);
                                  // refresh unbond period
                                  unbond.withdrawEpoch = stakeManager.epoch();
                                  unbonds[msg.sender] = unbond;
                                  StakingInfo logger = stakingLogger;
                                  logger.logShareBurned(validatorId, msg.sender, claimAmount, shares);
                                  logger.logStakeUpdate(validatorId);
                              }
                              function withdrawRewards() public {
                                  _withdrawRewards(false);
                              }
                              function withdrawRewardsPOL() public {
                                  _withdrawRewards(true);
                              }
                              function _withdrawRewards(bool pol) internal {
                                  uint256 rewards = _withdrawAndTransferReward(msg.sender, pol);
                                  require(rewards >= minAmount, "Too small rewards amount");
                              }
                              function migrateOut(address user, uint256 amount) external onlyOwner {
                                  _withdrawAndTransferReward(user, true);
                                  (uint256 totalStaked, uint256 rate) = getTotalStake(user);
                                  require(totalStaked >= amount, "Migrating too much");
                                  uint256 precision = _getRatePrecision();
                                  uint256 shares = amount.mul(precision).div(rate);
                                  _burn(user, shares);
                                  stakeManager.updateValidatorState(validatorId, -int256(amount));
                                  activeAmount = activeAmount.sub(amount);
                                  stakingLogger.logShareBurned(validatorId, user, amount, shares);
                                  stakingLogger.logStakeUpdate(validatorId);
                                  stakingLogger.logDelegatorUnstaked(validatorId, user, amount);
                              }
                              function migrateIn(address user, uint256 amount) external onlyOwner {
                                  _withdrawAndTransferReward(user, true);
                                  _buyShares(amount, 0, user);
                              } 
                              function unstakeClaimTokens() public {
                                  _unstakeClaimTokens(false);
                              }
                              function unstakeClaimTokensPOL() public {
                                  _unstakeClaimTokens(true);
                              }
                              function _unstakeClaimTokens(bool pol) internal {
                                  DelegatorUnbond memory unbond = unbonds[msg.sender];
                                  uint256 amount = _unstakeClaimTokens(unbond, pol);
                                  delete unbonds[msg.sender];
                                  stakingLogger.logDelegatorUnstaked(validatorId, msg.sender, amount);
                              }
                              function slash(
                                  uint256 validatorStake,
                                  uint256 delegatedAmount,
                                  uint256 totalAmountToSlash
                              ) external onlyOwner returns (uint256) {
                                  revert("Slashing disabled");
                              }
                              function updateDelegation(bool _delegation) external onlyOwner {
                                  delegation = _delegation;
                              }
                              function drain(
                                  address token,
                                  address payable destination,
                                  uint256 amount
                              ) external onlyOwner {
                                  revert("No draining.");
                              }
                              /**
                                  New shares exit API
                               */
                              function sellVoucher_new(uint256 claimAmount, uint256 maximumSharesToBurn) public {
                                  _sellVoucher_new(claimAmount, maximumSharesToBurn, false);
                              }
                              function sellVoucher_newPOL(uint256 claimAmount, uint256 maximumSharesToBurn) public {
                                  _sellVoucher_new(claimAmount, maximumSharesToBurn, true);
                              }
                              function _sellVoucher_new(uint256 claimAmount, uint256 maximumSharesToBurn, bool pol) public {
                                  (uint256 shares, uint256 _withdrawPoolShare) = _sellVoucher(claimAmount, maximumSharesToBurn, pol);
                                  uint256 unbondNonce = unbondNonces[msg.sender].add(1);
                                  DelegatorUnbond memory unbond = DelegatorUnbond({
                                      shares: _withdrawPoolShare,
                                      withdrawEpoch: stakeManager.epoch()
                                  });
                                  unbonds_new[msg.sender][unbondNonce] = unbond;
                                  unbondNonces[msg.sender] = unbondNonce;
                                  _getOrCacheEventsHub().logShareBurnedWithId(validatorId, msg.sender, claimAmount, shares, unbondNonce);
                                  stakingLogger.logStakeUpdate(validatorId);
                              }
                              function unstakeClaimTokens_new(uint256 unbondNonce) public {
                                  _unstakeClaimTokens_new(unbondNonce, false);
                              }
                              function unstakeClaimTokens_newPOL(uint256 unbondNonce) public {
                                  _unstakeClaimTokens_new(unbondNonce, true);
                              }
                              function _unstakeClaimTokens_new(uint256 unbondNonce, bool pol) internal {
                                  DelegatorUnbond memory unbond = unbonds_new[msg.sender][unbondNonce];
                                  uint256 amount = _unstakeClaimTokens(unbond, pol);
                                  delete unbonds_new[msg.sender][unbondNonce];
                                  _getOrCacheEventsHub().logDelegatorUnstakedWithId(validatorId, msg.sender, amount, unbondNonce);
                              }
                              /**
                                  Private Methods
                               */
                              function _getOrCacheEventsHub() private returns(EventsHub) {
                                  EventsHub _eventsHub = eventsHub;
                                  if (_eventsHub == EventsHub(0x0)) {
                                      _eventsHub = EventsHub(Registry(stakeManager.getRegistry()).contractMap(keccak256("eventsHub")));
                                      eventsHub = _eventsHub;
                                  }
                                  return _eventsHub;
                              }
                              function _getOrCachePOLToken() private returns (IERC20Permit) {
                                  IERC20Permit _polToken = polToken;
                                  if (_polToken == IERC20Permit(0x0)) {
                                      _polToken = IERC20Permit(Registry(stakeManager.getRegistry()).contractMap(keccak256("pol")));
                                      require(_polToken != IERC20Permit(0x0), "unset");
                                      polToken = _polToken;
                                  }
                                  return _polToken;
                              }
                              function _sellVoucher(
                                  uint256 claimAmount,
                                  uint256 maximumSharesToBurn,
                                  bool pol
                              ) private returns (uint256, uint256) {
                                  // first get how much staked in total and compare to target unstake amount
                                  (uint256 totalStaked, uint256 rate) = getTotalStake(msg.sender);
                                  require(totalStaked != 0 && totalStaked >= claimAmount, "Too much requested");
                                  // convert requested amount back to shares
                                  uint256 precision = _getRatePrecision();
                                  uint256 shares = claimAmount.mul(precision).div(rate);
                                  require(shares <= maximumSharesToBurn, "too much slippage");
                                  _withdrawAndTransferReward(msg.sender, pol);
                                  _burn(msg.sender, shares);
                                  stakeManager.updateValidatorState(validatorId, -int256(claimAmount));
                                  activeAmount = activeAmount.sub(claimAmount);
                                  uint256 _withdrawPoolShare = claimAmount.mul(precision).div(withdrawExchangeRate());
                                  withdrawPool = withdrawPool.add(claimAmount);
                                  withdrawShares = withdrawShares.add(_withdrawPoolShare);
                                  return (shares, _withdrawPoolShare);
                              }
                              function _unstakeClaimTokens(DelegatorUnbond memory unbond, bool pol) private returns (uint256) {
                                  uint256 shares = unbond.shares;
                                  require(
                                      unbond.withdrawEpoch.add(stakeManager.withdrawalDelay()) <= stakeManager.epoch() && shares > 0,
                                      "Incomplete withdrawal period"
                                  );
                                  uint256 _amount = withdrawExchangeRate().mul(shares).div(_getRatePrecision());
                                  withdrawShares = withdrawShares.sub(shares);
                                  withdrawPool = withdrawPool.sub(_amount);
                                  require(
                                      pol ? stakeManager.transferFundsPOL(validatorId, _amount, msg.sender) : stakeManager.transferFunds(validatorId, _amount, msg.sender),
                                      "Insufficent rewards"
                                  );
                                  return _amount;
                              }
                              function _getRatePrecision() private view returns (uint256) {
                                  // if foundation validator, use old precision
                                  if (validatorId < 8) {
                                      return EXCHANGE_RATE_PRECISION;
                                  }
                                  return EXCHANGE_RATE_HIGH_PRECISION;
                              }
                              function _calculateRewardPerShareWithRewards(uint256 accumulatedReward) private view returns (uint256) {
                                  uint256 _rewardPerShare = rewardPerShare;
                                  if (accumulatedReward != 0) {
                                      uint256 totalShares = totalSupply();
                                      
                                      if (totalShares != 0) {
                                          _rewardPerShare = _rewardPerShare.add(accumulatedReward.mul(REWARD_PRECISION).div(totalShares));
                                      }
                                  }
                                  return _rewardPerShare;
                              }
                              function _calculateReward(address user, uint256 _rewardPerShare) private view returns (uint256) {
                                  uint256 shares = balanceOf(user);
                                  if (shares == 0) {
                                      return 0;
                                  }
                                  uint256 _initialRewardPerShare = initalRewardPerShare[user];
                                  if (_initialRewardPerShare == _rewardPerShare) {
                                      return 0;
                                  }
                                  return _rewardPerShare.sub(_initialRewardPerShare).mul(shares).div(REWARD_PRECISION);
                              }
                              function _withdrawReward(address user) private returns (uint256) {
                                  uint256 _rewardPerShare = _calculateRewardPerShareWithRewards(
                                      stakeManager.withdrawDelegatorsReward(validatorId)
                                  );
                                  uint256 liquidRewards = _calculateReward(user, _rewardPerShare);
                                  
                                  rewardPerShare = _rewardPerShare;
                                  initalRewardPerShare[user] = _rewardPerShare;
                                  return liquidRewards;
                              }
                              function _withdrawAndTransferReward(address user, bool pol) private returns (uint256) {
                                  uint256 liquidRewards = _withdrawReward(user);
                                  if (liquidRewards != 0) {
                                      require(
                                          pol ? stakeManager.transferFundsPOL(validatorId, liquidRewards, user) : stakeManager.transferFunds(validatorId, liquidRewards, user),
                                          "Insufficent rewards"
                                      );
                                      stakingLogger.logDelegatorClaimRewards(validatorId, user, liquidRewards);
                                  }
                                  return liquidRewards;
                              }
                              function _buyShares(
                                  uint256 _amount,
                                  uint256 _minSharesToMint,
                                  address user
                              ) private onlyWhenUnlocked returns (uint256) {
                                  require(delegation, "Delegation is disabled");
                                  uint256 rate = exchangeRate();
                                  uint256 precision = _getRatePrecision();
                                  uint256 shares = _amount.mul(precision).div(rate);
                                  require(shares >= _minSharesToMint, "Too much slippage");
                                  require(unbonds[user].shares == 0, "Ongoing exit");
                                  _mint(user, shares);
                                  // clamp amount of tokens in case resulted shares requires less tokens than anticipated
                                  _amount = rate.mul(shares).div(precision);
                                  stakeManager.updateValidatorState(validatorId, int256(_amount));
                                  activeAmount = activeAmount.add(_amount);
                                  StakingInfo logger = stakingLogger;
                                  logger.logShareMinted(validatorId, user, _amount, shares);
                                  logger.logStakeUpdate(validatorId);
                                  return _amount;
                              }
                              function transferPOL(address to, uint256 value) public returns (bool) {
                                  _transfer(to, value, true);
                                  return true;
                              }
                              function transfer(address to, uint256 value) public returns (bool) {
                                  _transfer(to, value, false);
                                  return true;
                              }
                              function _transfer(address to, uint256 value, bool pol) internal {
                                  address from = msg.sender;
                                  // get rewards for recipient
                                  _withdrawAndTransferReward(to, pol);
                                  // convert rewards to shares
                                  _withdrawAndTransferReward(from, pol);
                                  // move shares to recipient
                                  super._transfer(from, to, value);
                                  _getOrCacheEventsHub().logSharesTransfer(validatorId, from, to, value);
                              }
                          }
                          pragma solidity ^0.5.2;
                          import {Governable} from "./governance/Governable.sol";
                          import {IWithdrawManager} from "../root/withdrawManager/IWithdrawManager.sol";
                          contract Registry is Governable {
                              // @todo hardcode constants
                              bytes32 private constant WETH_TOKEN = keccak256("wethToken");
                              bytes32 private constant DEPOSIT_MANAGER = keccak256("depositManager");
                              bytes32 private constant STAKE_MANAGER = keccak256("stakeManager");
                              bytes32 private constant VALIDATOR_SHARE = keccak256("validatorShare");
                              bytes32 private constant WITHDRAW_MANAGER = keccak256("withdrawManager");
                              bytes32 private constant CHILD_CHAIN = keccak256("childChain");
                              bytes32 private constant STATE_SENDER = keccak256("stateSender");
                              bytes32 private constant SLASHING_MANAGER = keccak256("slashingManager");
                              address public erc20Predicate;
                              address public erc721Predicate;
                              mapping(bytes32 => address) public contractMap;
                              mapping(address => address) public rootToChildToken;
                              mapping(address => address) public childToRootToken;
                              mapping(address => bool) public proofValidatorContracts;
                              mapping(address => bool) public isERC721;
                              enum Type {Invalid, ERC20, ERC721, Custom}
                              struct Predicate {
                                  Type _type;
                              }
                              mapping(address => Predicate) public predicates;
                              event TokenMapped(address indexed rootToken, address indexed childToken);
                              event ProofValidatorAdded(address indexed validator, address indexed from);
                              event ProofValidatorRemoved(address indexed validator, address indexed from);
                              event PredicateAdded(address indexed predicate, address indexed from);
                              event PredicateRemoved(address indexed predicate, address indexed from);
                              event ContractMapUpdated(bytes32 indexed key, address indexed previousContract, address indexed newContract);
                              constructor(address _governance) public Governable(_governance) {}
                              function updateContractMap(bytes32 _key, address _address) external onlyGovernance {
                                  emit ContractMapUpdated(_key, contractMap[_key], _address);
                                  contractMap[_key] = _address;
                              }
                              /**
                               * @dev Map root token to child token
                               * @param _rootToken Token address on the root chain
                               * @param _childToken Token address on the child chain
                               * @param _isERC721 Is the token being mapped ERC721
                               */
                              function mapToken(
                                  address _rootToken,
                                  address _childToken,
                                  bool _isERC721
                              ) external onlyGovernance {
                                  require(_rootToken != address(0x0) && _childToken != address(0x0), "INVALID_TOKEN_ADDRESS");
                                  rootToChildToken[_rootToken] = _childToken;
                                  childToRootToken[_childToken] = _rootToken;
                                  isERC721[_rootToken] = _isERC721;
                                  IWithdrawManager(contractMap[WITHDRAW_MANAGER]).createExitQueue(_rootToken);
                                  emit TokenMapped(_rootToken, _childToken);
                              }
                              function addErc20Predicate(address predicate) public onlyGovernance {
                                  require(predicate != address(0x0), "Can not add null address as predicate");
                                  erc20Predicate = predicate;
                                  addPredicate(predicate, Type.ERC20);
                              }
                              function addErc721Predicate(address predicate) public onlyGovernance {
                                  erc721Predicate = predicate;
                                  addPredicate(predicate, Type.ERC721);
                              }
                              function addPredicate(address predicate, Type _type) public onlyGovernance {
                                  require(predicates[predicate]._type == Type.Invalid, "Predicate already added");
                                  predicates[predicate]._type = _type;
                                  emit PredicateAdded(predicate, msg.sender);
                              }
                              function removePredicate(address predicate) public onlyGovernance {
                                  require(predicates[predicate]._type != Type.Invalid, "Predicate does not exist");
                                  delete predicates[predicate];
                                  emit PredicateRemoved(predicate, msg.sender);
                              }
                              function getValidatorShareAddress() public view returns (address) {
                                  return contractMap[VALIDATOR_SHARE];
                              }
                              function getWethTokenAddress() public view returns (address) {
                                  return contractMap[WETH_TOKEN];
                              }
                              function getDepositManagerAddress() public view returns (address) {
                                  return contractMap[DEPOSIT_MANAGER];
                              }
                              function getStakeManagerAddress() public view returns (address) {
                                  return contractMap[STAKE_MANAGER];
                              }
                              function getSlashingManagerAddress() public view returns (address) {
                                  return contractMap[SLASHING_MANAGER];
                              }
                              function getWithdrawManagerAddress() public view returns (address) {
                                  return contractMap[WITHDRAW_MANAGER];
                              }
                              function getChildChainAndStateSender() public view returns (address, address) {
                                  return (contractMap[CHILD_CHAIN], contractMap[STATE_SENDER]);
                              }
                              function isTokenMapped(address _token) public view returns (bool) {
                                  return rootToChildToken[_token] != address(0x0);
                              }
                              function isTokenMappedAndIsErc721(address _token) public view returns (bool) {
                                  require(isTokenMapped(_token), "TOKEN_NOT_MAPPED");
                                  return isERC721[_token];
                              }
                              function isTokenMappedAndGetPredicate(address _token) public view returns (address) {
                                  if (isTokenMappedAndIsErc721(_token)) {
                                      return erc721Predicate;
                                  }
                                  return erc20Predicate;
                              }
                              function isChildTokenErc721(address childToken) public view returns (bool) {
                                  address rootToken = childToRootToken[childToken];
                                  require(rootToken != address(0x0), "Child token is not mapped");
                                  return isERC721[rootToken];
                              }
                          }
                          pragma solidity ^0.5.2;
                          import {ERC20} from "openzeppelin-solidity/contracts/token/ERC20/ERC20.sol";
                          contract ERC20NonTradable is ERC20 {
                              function _approve(
                                  address owner,
                                  address spender,
                                  uint256 value
                              ) internal {
                                  revert("disabled");
                              }
                          }
                          pragma solidity ^0.5.2;
                          import "./IERC20.sol";
                          import "../../math/SafeMath.sol";
                          /**
                           * @title Standard ERC20 token
                           *
                           * @dev Implementation of the basic standard token.
                           * https://eips.ethereum.org/EIPS/eip-20
                           * Originally based on code by FirstBlood:
                           * https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol
                           *
                           * This implementation emits additional Approval events, allowing applications to reconstruct the allowance status for
                           * all accounts just by listening to said events. Note that this isn't required by the specification, and other
                           * compliant implementations may not do it.
                           */
                          contract ERC20 is IERC20 {
                              using SafeMath for uint256;
                              mapping (address => uint256) private _balances;
                              mapping (address => mapping (address => uint256)) private _allowed;
                              uint256 private _totalSupply;
                              /**
                               * @dev Total number of tokens in existence
                               */
                              function totalSupply() public view returns (uint256) {
                                  return _totalSupply;
                              }
                              /**
                               * @dev Gets the balance of the specified address.
                               * @param owner The address to query the balance of.
                               * @return A uint256 representing the amount owned by the passed address.
                               */
                              function balanceOf(address owner) public view returns (uint256) {
                                  return _balances[owner];
                              }
                              /**
                               * @dev Function to check the amount of tokens that an owner allowed to a spender.
                               * @param owner address The address which owns the funds.
                               * @param spender address The address which will spend the funds.
                               * @return A uint256 specifying the amount of tokens still available for the spender.
                               */
                              function allowance(address owner, address spender) public view returns (uint256) {
                                  return _allowed[owner][spender];
                              }
                              /**
                               * @dev Transfer token to a specified address
                               * @param to The address to transfer to.
                               * @param value The amount to be transferred.
                               */
                              function transfer(address to, uint256 value) public returns (bool) {
                                  _transfer(msg.sender, to, value);
                                  return true;
                              }
                              /**
                               * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
                               * Beware that changing an allowance with this method brings the risk that someone may use both the old
                               * and the new allowance by unfortunate transaction ordering. One possible solution to mitigate this
                               * race condition is to first reduce the spender's allowance to 0 and set the desired value afterwards:
                               * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
                               * @param spender The address which will spend the funds.
                               * @param value The amount of tokens to be spent.
                               */
                              function approve(address spender, uint256 value) public returns (bool) {
                                  _approve(msg.sender, spender, value);
                                  return true;
                              }
                              /**
                               * @dev Transfer tokens from one address to another.
                               * Note that while this function emits an Approval event, this is not required as per the specification,
                               * and other compliant implementations may not emit the event.
                               * @param from address The address which you want to send tokens from
                               * @param to address The address which you want to transfer to
                               * @param value uint256 the amount of tokens to be transferred
                               */
                              function transferFrom(address from, address to, uint256 value) public returns (bool) {
                                  _transfer(from, to, value);
                                  _approve(from, msg.sender, _allowed[from][msg.sender].sub(value));
                                  return true;
                              }
                              /**
                               * @dev Increase the amount of tokens that an owner allowed to a spender.
                               * approve should be called when _allowed[msg.sender][spender] == 0. To increment
                               * allowed value is better to use this function to avoid 2 calls (and wait until
                               * the first transaction is mined)
                               * From MonolithDAO Token.sol
                               * Emits an Approval event.
                               * @param spender The address which will spend the funds.
                               * @param addedValue The amount of tokens to increase the allowance by.
                               */
                              function increaseAllowance(address spender, uint256 addedValue) public returns (bool) {
                                  _approve(msg.sender, spender, _allowed[msg.sender][spender].add(addedValue));
                                  return true;
                              }
                              /**
                               * @dev Decrease the amount of tokens that an owner allowed to a spender.
                               * approve should be called when _allowed[msg.sender][spender] == 0. To decrement
                               * allowed value is better to use this function to avoid 2 calls (and wait until
                               * the first transaction is mined)
                               * From MonolithDAO Token.sol
                               * Emits an Approval event.
                               * @param spender The address which will spend the funds.
                               * @param subtractedValue The amount of tokens to decrease the allowance by.
                               */
                              function decreaseAllowance(address spender, uint256 subtractedValue) public returns (bool) {
                                  _approve(msg.sender, spender, _allowed[msg.sender][spender].sub(subtractedValue));
                                  return true;
                              }
                              /**
                               * @dev Transfer token for a specified addresses
                               * @param from The address to transfer from.
                               * @param to The address to transfer to.
                               * @param value The amount to be transferred.
                               */
                              function _transfer(address from, address to, uint256 value) internal {
                                  require(to != address(0));
                                  _balances[from] = _balances[from].sub(value);
                                  _balances[to] = _balances[to].add(value);
                                  emit Transfer(from, to, value);
                              }
                              /**
                               * @dev Internal function that mints an amount of the token and assigns it to
                               * an account. This encapsulates the modification of balances such that the
                               * proper events are emitted.
                               * @param account The account that will receive the created tokens.
                               * @param value The amount that will be created.
                               */
                              function _mint(address account, uint256 value) internal {
                                  require(account != address(0));
                                  _totalSupply = _totalSupply.add(value);
                                  _balances[account] = _balances[account].add(value);
                                  emit Transfer(address(0), account, value);
                              }
                              /**
                               * @dev Internal function that burns an amount of the token of a given
                               * account.
                               * @param account The account whose tokens will be burnt.
                               * @param value The amount that will be burnt.
                               */
                              function _burn(address account, uint256 value) internal {
                                  require(account != address(0));
                                  _totalSupply = _totalSupply.sub(value);
                                  _balances[account] = _balances[account].sub(value);
                                  emit Transfer(account, address(0), value);
                              }
                              /**
                               * @dev Approve an address to spend another addresses' tokens.
                               * @param owner The address that owns the tokens.
                               * @param spender The address that will spend the tokens.
                               * @param value The number of tokens that can be spent.
                               */
                              function _approve(address owner, address spender, uint256 value) internal {
                                  require(spender != address(0));
                                  require(owner != address(0));
                                  _allowed[owner][spender] = value;
                                  emit Approval(owner, spender, value);
                              }
                              /**
                               * @dev Internal function that burns an amount of the token of a given
                               * account, deducting from the sender's allowance for said account. Uses the
                               * internal burn function.
                               * Emits an Approval event (reflecting the reduced allowance).
                               * @param account The account whose tokens will be burnt.
                               * @param value The amount that will be burnt.
                               */
                              function _burnFrom(address account, uint256 value) internal {
                                  _burn(account, value);
                                  _approve(account, msg.sender, _allowed[account][msg.sender].sub(value));
                              }
                          }
                          pragma solidity ^0.5.2;
                          import {Registry} from "../common/Registry.sol";
                          import {SafeMath} from "openzeppelin-solidity/contracts/math/SafeMath.sol";
                          import {Ownable} from "openzeppelin-solidity/contracts/ownership/Ownable.sol";
                          // dummy interface to avoid cyclic dependency
                          contract IStakeManagerLocal {
                              enum Status {Inactive, Active, Locked, Unstaked}
                              struct Validator {
                                  uint256 amount;
                                  uint256 reward;
                                  uint256 activationEpoch;
                                  uint256 deactivationEpoch;
                                  uint256 jailTime;
                                  address signer;
                                  address contractAddress;
                                  Status status;
                              }
                              mapping(uint256 => Validator) public validators;
                              bytes32 public accountStateRoot;
                              uint256 public activeAmount; // delegation amount from validator contract
                              uint256 public validatorRewards;
                              function currentValidatorSetTotalStake() public view returns (uint256);
                              // signer to Validator mapping
                              function signerToValidator(address validatorAddress)
                                  public
                                  view
                                  returns (uint256);
                              function isValidator(uint256 validatorId) public view returns (bool);
                          }
                          contract StakingInfo is Ownable {
                              using SafeMath for uint256;
                              mapping(uint256 => uint256) public validatorNonce;
                              /// @dev Emitted when validator stakes in '_stakeFor()' in StakeManager.
                              /// @param signer validator address.
                              /// @param validatorId unique integer to identify a validator.
                              /// @param nonce to synchronize the events in heimdal.
                              /// @param activationEpoch validator's first epoch as proposer.
                              /// @param amount staking amount.
                              /// @param total total staking amount.
                              /// @param signerPubkey public key of the validator
                              event Staked(
                                  address indexed signer,
                                  uint256 indexed validatorId,
                                  uint256 nonce,
                                  uint256 indexed activationEpoch,
                                  uint256 amount,
                                  uint256 total,
                                  bytes signerPubkey
                              );
                              /// @dev Emitted when validator unstakes in 'unstakeClaim()'
                              /// @param user address of the validator.
                              /// @param validatorId unique integer to identify a validator.
                              /// @param amount staking amount.
                              /// @param total total staking amount.
                              event Unstaked(
                                  address indexed user,
                                  uint256 indexed validatorId,
                                  uint256 amount,
                                  uint256 total
                              );
                              /// @dev Emitted when validator unstakes in '_unstake()'.
                              /// @param user address of the validator.
                              /// @param validatorId unique integer to identify a validator.
                              /// @param nonce to synchronize the events in heimdal.
                              /// @param deactivationEpoch last epoch for validator.
                              /// @param amount staking amount.
                              event UnstakeInit(
                                  address indexed user,
                                  uint256 indexed validatorId,
                                  uint256 nonce,
                                  uint256 deactivationEpoch,
                                  uint256 indexed amount
                              );
                              /// @dev Emitted when the validator public key is updated in 'updateSigner()'.
                              /// @param validatorId unique integer to identify a validator.
                              /// @param nonce to synchronize the events in heimdal.
                              /// @param oldSigner old address of the validator.
                              /// @param newSigner new address of the validator.
                              /// @param signerPubkey public key of the validator.
                              event SignerChange(
                                  uint256 indexed validatorId,
                                  uint256 nonce,
                                  address indexed oldSigner,
                                  address indexed newSigner,
                                  bytes signerPubkey
                              );
                              event Restaked(uint256 indexed validatorId, uint256 amount, uint256 total);
                              event Jailed(
                                  uint256 indexed validatorId,
                                  uint256 indexed exitEpoch,
                                  address indexed signer
                              );
                              event UnJailed(uint256 indexed validatorId, address indexed signer);
                              event Slashed(uint256 indexed nonce, uint256 indexed amount);
                              event ThresholdChange(uint256 newThreshold, uint256 oldThreshold);
                              event DynastyValueChange(uint256 newDynasty, uint256 oldDynasty);
                              event ProposerBonusChange(
                                  uint256 newProposerBonus,
                                  uint256 oldProposerBonus
                              );
                              event RewardUpdate(uint256 newReward, uint256 oldReward);
                              /// @dev Emitted when validator confirms the auction bid and at the time of restaking in confirmAuctionBid() and restake().
                              /// @param validatorId unique integer to identify a validator.
                              /// @param nonce to synchronize the events in heimdal.
                              /// @param newAmount the updated stake amount.
                              event StakeUpdate(
                                  uint256 indexed validatorId,
                                  uint256 indexed nonce,
                                  uint256 indexed newAmount
                              );
                              event ClaimRewards(
                                  uint256 indexed validatorId,
                                  uint256 indexed amount,
                                  uint256 indexed totalAmount
                              );
                              event StartAuction(
                                  uint256 indexed validatorId,
                                  uint256 indexed amount,
                                  uint256 indexed auctionAmount
                              );
                              event ConfirmAuction(
                                  uint256 indexed newValidatorId,
                                  uint256 indexed oldValidatorId,
                                  uint256 indexed amount
                              );
                              event TopUpFee(address indexed user, uint256 indexed fee);
                              event ClaimFee(address indexed user, uint256 indexed fee);
                              // Delegator events
                              event ShareMinted(
                                  uint256 indexed validatorId,
                                  address indexed user,
                                  uint256 indexed amount,
                                  uint256 tokens
                              );
                              event ShareBurned(
                                  uint256 indexed validatorId,
                                  address indexed user,
                                  uint256 indexed amount,
                                  uint256 tokens
                              );
                              event DelegatorClaimedRewards(
                                  uint256 indexed validatorId,
                                  address indexed user,
                                  uint256 indexed rewards
                              );
                              event DelegatorRestaked(
                                  uint256 indexed validatorId,
                                  address indexed user,
                                  uint256 indexed totalStaked
                              );
                              event DelegatorUnstaked(
                                  uint256 indexed validatorId,
                                  address indexed user,
                                  uint256 amount
                              );
                              event UpdateCommissionRate(
                                  uint256 indexed validatorId,
                                  uint256 indexed newCommissionRate,
                                  uint256 indexed oldCommissionRate
                              );
                              Registry public registry;
                              modifier onlyValidatorContract(uint256 validatorId) {
                                  address _contract;
                                  (, , , , , , _contract, ) = IStakeManagerLocal(
                                      registry.getStakeManagerAddress()
                                  )
                                      .validators(validatorId);
                                  require(_contract == msg.sender,
                                  "Invalid sender, not validator");
                                  _;
                              }
                              modifier StakeManagerOrValidatorContract(uint256 validatorId) {
                                  address _contract;
                                  address _stakeManager = registry.getStakeManagerAddress();
                                  (, , , , , , _contract, ) = IStakeManagerLocal(_stakeManager).validators(
                                      validatorId
                                  );
                                  require(_contract == msg.sender || _stakeManager == msg.sender,
                                  "Invalid sender, not stake manager or validator contract");
                                  _;
                              }
                              modifier onlyStakeManager() {
                                  require(registry.getStakeManagerAddress() == msg.sender,
                                  "Invalid sender, not stake manager");
                                  _;
                              }
                              modifier onlySlashingManager() {
                                  require(registry.getSlashingManagerAddress() == msg.sender,
                                  "Invalid sender, not slashing manager");
                                  _;
                              }
                              constructor(address _registry) public {
                                  registry = Registry(_registry);
                              }
                              function updateNonce(
                                  uint256[] calldata validatorIds,
                                  uint256[] calldata nonces
                              ) external onlyOwner {
                                  require(validatorIds.length == nonces.length, "args length mismatch");
                                  for (uint256 i = 0; i < validatorIds.length; ++i) {
                                      validatorNonce[validatorIds[i]] = nonces[i];
                                  }
                              } 
                              function logStaked(
                                  address signer,
                                  bytes memory signerPubkey,
                                  uint256 validatorId,
                                  uint256 activationEpoch,
                                  uint256 amount,
                                  uint256 total
                              ) public onlyStakeManager {
                                  validatorNonce[validatorId] = validatorNonce[validatorId].add(1);
                                  emit Staked(
                                      signer,
                                      validatorId,
                                      validatorNonce[validatorId],
                                      activationEpoch,
                                      amount,
                                      total,
                                      signerPubkey
                                  );
                              }
                              function logUnstaked(
                                  address user,
                                  uint256 validatorId,
                                  uint256 amount,
                                  uint256 total
                              ) public onlyStakeManager {
                                  emit Unstaked(user, validatorId, amount, total);
                              }
                              function logUnstakeInit(
                                  address user,
                                  uint256 validatorId,
                                  uint256 deactivationEpoch,
                                  uint256 amount
                              ) public onlyStakeManager {
                                  validatorNonce[validatorId] = validatorNonce[validatorId].add(1);
                                  emit UnstakeInit(
                                      user,
                                      validatorId,
                                      validatorNonce[validatorId],
                                      deactivationEpoch,
                                      amount
                                  );
                              }
                              function logSignerChange(
                                  uint256 validatorId,
                                  address oldSigner,
                                  address newSigner,
                                  bytes memory signerPubkey
                              ) public onlyStakeManager {
                                  validatorNonce[validatorId] = validatorNonce[validatorId].add(1);
                                  emit SignerChange(
                                      validatorId,
                                      validatorNonce[validatorId],
                                      oldSigner,
                                      newSigner,
                                      signerPubkey
                                  );
                              }
                              function logRestaked(uint256 validatorId, uint256 amount, uint256 total)
                                  public
                                  onlyStakeManager
                              {
                                  emit Restaked(validatorId, amount, total);
                              }
                              function logJailed(uint256 validatorId, uint256 exitEpoch, address signer)
                                  public
                                  onlyStakeManager
                              {
                                  emit Jailed(validatorId, exitEpoch, signer);
                              }
                              function logUnjailed(uint256 validatorId, address signer)
                                  public
                                  onlyStakeManager
                              {
                                  emit UnJailed(validatorId, signer);
                              }
                              function logSlashed(uint256 nonce, uint256 amount)
                                  public
                                  onlySlashingManager
                              {
                                  emit Slashed(nonce, amount);
                              }
                              function logThresholdChange(uint256 newThreshold, uint256 oldThreshold)
                                  public
                                  onlyStakeManager
                              {
                                  emit ThresholdChange(newThreshold, oldThreshold);
                              }
                              function logDynastyValueChange(uint256 newDynasty, uint256 oldDynasty)
                                  public
                                  onlyStakeManager
                              {
                                  emit DynastyValueChange(newDynasty, oldDynasty);
                              }
                              function logProposerBonusChange(
                                  uint256 newProposerBonus,
                                  uint256 oldProposerBonus
                              ) public onlyStakeManager {
                                  emit ProposerBonusChange(newProposerBonus, oldProposerBonus);
                              }
                              function logRewardUpdate(uint256 newReward, uint256 oldReward)
                                  public
                                  onlyStakeManager
                              {
                                  emit RewardUpdate(newReward, oldReward);
                              }
                              function logStakeUpdate(uint256 validatorId)
                                  public
                                  StakeManagerOrValidatorContract(validatorId)
                              {
                                  validatorNonce[validatorId] = validatorNonce[validatorId].add(1);
                                  emit StakeUpdate(
                                      validatorId,
                                      validatorNonce[validatorId],
                                      totalValidatorStake(validatorId)
                                  );
                              }
                              function logClaimRewards(
                                  uint256 validatorId,
                                  uint256 amount,
                                  uint256 totalAmount
                              ) public onlyStakeManager {
                                  emit ClaimRewards(validatorId, amount, totalAmount);
                              }
                              function logStartAuction(
                                  uint256 validatorId,
                                  uint256 amount,
                                  uint256 auctionAmount
                              ) public onlyStakeManager {
                                  emit StartAuction(validatorId, amount, auctionAmount);
                              }
                              function logConfirmAuction(
                                  uint256 newValidatorId,
                                  uint256 oldValidatorId,
                                  uint256 amount
                              ) public onlyStakeManager {
                                  emit ConfirmAuction(newValidatorId, oldValidatorId, amount);
                              }
                              function logTopUpFee(address user, uint256 fee) public onlyStakeManager {
                                  emit TopUpFee(user, fee);
                              }
                              function logClaimFee(address user, uint256 fee) public onlyStakeManager {
                                  emit ClaimFee(user, fee);
                              }
                              function getStakerDetails(uint256 validatorId)
                                  public
                                  view
                                  returns (
                                      uint256 amount,
                                      uint256 reward,
                                      uint256 activationEpoch,
                                      uint256 deactivationEpoch,
                                      address signer,
                                      uint256 _status
                                  )
                              {
                                  IStakeManagerLocal stakeManager = IStakeManagerLocal(
                                      registry.getStakeManagerAddress()
                                  );
                                  address _contract;
                                  IStakeManagerLocal.Status status;
                                  (
                                      amount,
                                      reward,
                                      activationEpoch,
                                      deactivationEpoch,
                                      ,
                                      signer,
                                      _contract,
                                      status
                                  ) = stakeManager.validators(validatorId);
                                  _status = uint256(status);
                                  if (_contract != address(0x0)) {
                                      reward += IStakeManagerLocal(_contract).validatorRewards();
                                  }
                              }
                              function totalValidatorStake(uint256 validatorId)
                                  public
                                  view
                                  returns (uint256 validatorStake)
                              {
                                  address contractAddress;
                                  (validatorStake, , , , , , contractAddress, ) = IStakeManagerLocal(
                                      registry.getStakeManagerAddress()
                                  )
                                      .validators(validatorId);
                                  if (contractAddress != address(0x0)) {
                                      validatorStake += IStakeManagerLocal(contractAddress).activeAmount();
                                  }
                              }
                              function getAccountStateRoot()
                                  public
                                  view
                                  returns (bytes32 accountStateRoot)
                              {
                                  accountStateRoot = IStakeManagerLocal(registry.getStakeManagerAddress())
                                      .accountStateRoot();
                              }
                              function getValidatorContractAddress(uint256 validatorId)
                                  public
                                  view
                                  returns (address ValidatorContract)
                              {
                                  (, , , , , , ValidatorContract, ) = IStakeManagerLocal(
                                      registry.getStakeManagerAddress()
                                  )
                                      .validators(validatorId);
                              }
                              // validator Share contract logging func
                              function logShareMinted(
                                  uint256 validatorId,
                                  address user,
                                  uint256 amount,
                                  uint256 tokens
                              ) public onlyValidatorContract(validatorId) {
                                  emit ShareMinted(validatorId, user, amount, tokens);
                              }
                              function logShareBurned(
                                  uint256 validatorId,
                                  address user,
                                  uint256 amount,
                                  uint256 tokens
                              ) public onlyValidatorContract(validatorId) {
                                  emit ShareBurned(validatorId, user, amount, tokens);
                              }
                              function logDelegatorClaimRewards(
                                  uint256 validatorId,
                                  address user,
                                  uint256 rewards
                              ) public onlyValidatorContract(validatorId) {
                                  emit DelegatorClaimedRewards(validatorId, user, rewards);
                              }
                              function logDelegatorRestaked(
                                  uint256 validatorId,
                                  address user,
                                  uint256 totalStaked
                              ) public onlyValidatorContract(validatorId) {
                                  emit DelegatorRestaked(validatorId, user, totalStaked);
                              }
                              function logDelegatorUnstaked(uint256 validatorId, address user, uint256 amount)
                                  public
                                  onlyValidatorContract(validatorId)
                              {
                                  emit DelegatorUnstaked(validatorId, user, amount);
                              }
                              // deprecated
                              function logUpdateCommissionRate(
                                  uint256 validatorId,
                                  uint256 newCommissionRate,
                                  uint256 oldCommissionRate
                              ) public onlyValidatorContract(validatorId) {
                                  emit UpdateCommissionRate(
                                      validatorId,
                                      newCommissionRate,
                                      oldCommissionRate
                                  );
                              }
                          }
                          pragma solidity ^0.5.2;
                          import {Registry} from "../common/Registry.sol";
                          import {Initializable} from "../common/mixin/Initializable.sol";
                          contract IStakeManagerEventsHub {
                              struct Validator {
                                  uint256 amount;
                                  uint256 reward;
                                  uint256 activationEpoch;
                                  uint256 deactivationEpoch;
                                  uint256 jailTime;
                                  address signer;
                                  address contractAddress;
                              }
                              mapping(uint256 => Validator) public validators;
                          }
                          contract EventsHub is Initializable {
                              Registry public registry;
                              modifier onlyValidatorContract(uint256 validatorId) {
                                  address _contract;
                                  (, , , , , , _contract) = IStakeManagerEventsHub(registry.getStakeManagerAddress()).validators(validatorId);
                                  require(_contract == msg.sender, "not validator");
                                  _;
                              }
                              modifier onlyStakeManager() {
                                  require(registry.getStakeManagerAddress() == msg.sender,
                                  "Invalid sender, not stake manager");
                                  _;
                              }
                              function initialize(Registry _registry) external initializer {
                                  registry = _registry;
                              }
                              event ShareBurnedWithId(
                                  uint256 indexed validatorId,
                                  address indexed user,
                                  uint256 indexed amount,
                                  uint256 tokens,
                                  uint256 nonce
                              );
                              function logShareBurnedWithId(
                                  uint256 validatorId,
                                  address user,
                                  uint256 amount,
                                  uint256 tokens,
                                  uint256 nonce
                              ) public onlyValidatorContract(validatorId) {
                                  emit ShareBurnedWithId(validatorId, user, amount, tokens, nonce);
                              }
                              event DelegatorUnstakeWithId(
                                  uint256 indexed validatorId,
                                  address indexed user,
                                  uint256 amount,
                                  uint256 nonce
                              );
                              function logDelegatorUnstakedWithId(
                                  uint256 validatorId,
                                  address user,
                                  uint256 amount,
                                  uint256 nonce
                              ) public onlyValidatorContract(validatorId) {
                                  emit DelegatorUnstakeWithId(validatorId, user, amount, nonce);
                              }
                              event RewardParams(
                                  uint256 rewardDecreasePerCheckpoint,
                                  uint256 maxRewardedCheckpoints,
                                  uint256 checkpointRewardDelta
                              );
                              function logRewardParams(
                                  uint256 rewardDecreasePerCheckpoint,
                                  uint256 maxRewardedCheckpoints,
                                  uint256 checkpointRewardDelta
                              ) public onlyStakeManager {
                                  emit RewardParams(rewardDecreasePerCheckpoint, maxRewardedCheckpoints, checkpointRewardDelta);
                              }
                              event UpdateCommissionRate(
                                  uint256 indexed validatorId,
                                  uint256 indexed newCommissionRate,
                                  uint256 indexed oldCommissionRate
                              );
                              function logUpdateCommissionRate(
                                  uint256 validatorId,
                                  uint256 newCommissionRate,
                                  uint256 oldCommissionRate
                              ) public onlyStakeManager {
                                  emit UpdateCommissionRate(
                                      validatorId,
                                      newCommissionRate,
                                      oldCommissionRate
                                  );
                              }
                              event SharesTransfer(
                                  uint256 indexed validatorId,
                                  address indexed from,
                                  address indexed to,
                                  uint256 value
                              );
                              function logSharesTransfer(
                                  uint256 validatorId,
                                  address from,
                                  address to,
                                  uint256 value
                              ) public onlyValidatorContract(validatorId) {
                                  emit SharesTransfer(validatorId, from, to, value);
                              }
                          }
                          pragma solidity ^0.5.2;
                          import { Lockable } from "./Lockable.sol";
                          import { Ownable } from "openzeppelin-solidity/contracts/ownership/Ownable.sol";
                          contract OwnableLockable is Lockable, Ownable {
                              function lock() public onlyOwner {
                                  super.lock();
                              }
                              function unlock() public onlyOwner {
                                  super.unlock();
                              }
                          }
                          pragma solidity 0.5.17;
                          contract IStakeManager {
                              // validator replacement
                              function startAuction(
                                  uint256 validatorId,
                                  uint256 amount,
                                  bool acceptDelegation,
                                  bytes calldata signerPubkey
                              ) external;
                              function confirmAuctionBid(uint256 validatorId, uint256 heimdallFee) external;
                              function transferFunds(
                                  uint256 validatorId,
                                  uint256 amount,
                                  address delegator
                              ) external returns (bool);
                              function transferFundsPOL(
                                  uint256 validatorId, 
                                  uint256 amount, 
                                  address delegator
                              ) external returns (bool);
                              function delegationDeposit(
                                  uint256 validatorId,
                                  uint256 amount,
                                  address delegator
                              ) external returns (bool);
                              function delegationDepositPOL(
                                  uint256 validatorId, 
                                  uint256 amount, 
                                  address delegator
                              ) external returns (bool);
                              function unstake(uint256 validatorId) external;
                              function unstakePOL(uint256 validatorId) external;
                              function totalStakedFor(address addr) external view returns (uint256);
                              function stakeFor(
                                  address user,
                                  uint256 amount,
                                  uint256 heimdallFee,
                                  bool acceptDelegation,
                                  bytes memory signerPubkey
                              ) public;
                              function stakeForPOL(
                                  address user,
                                  uint256 amount,
                                  uint256 heimdallFee,
                                  bool acceptDelegation,
                                  bytes memory signerPubkey
                              ) public;
                              function checkSignatures(
                                  uint256 blockInterval,
                                  bytes32 voteHash,
                                  bytes32 stateRoot,
                                  address proposer,
                                  uint[3][] calldata sigs
                              ) external returns (uint256);
                              function updateValidatorState(uint256 validatorId, int256 amount) public;
                              function ownerOf(uint256 tokenId) public view returns (address);
                              function slash(bytes calldata slashingInfoList) external returns (uint256);
                              function validatorStake(uint256 validatorId) public view returns (uint256);
                              function epoch() public view returns (uint256);
                              function getRegistry() public view returns (address);
                              function withdrawalDelay() public view returns (uint256);
                              function delegatedAmount(uint256 validatorId) public view returns(uint256);
                              function decreaseValidatorDelegatedAmount(uint256 validatorId, uint256 amount) public;
                              function withdrawDelegatorsReward(uint256 validatorId) public returns(uint256);
                              function delegatorsReward(uint256 validatorId) public view returns(uint256);
                              function dethroneAndStake(
                                  address auctionUser,
                                  uint256 heimdallFee,
                                  uint256 validatorId,
                                  uint256 auctionAmount,
                                  bool acceptDelegation,
                                  bytes calldata signerPubkey
                              ) external;
                          }
                          pragma solidity 0.5.17;
                          // note this contract interface is only for stakeManager use
                          contract IValidatorShare {
                              function withdrawRewards() public;
                              function unstakeClaimTokens() public;
                              function getLiquidRewards(address user) public view returns (uint256);
                              
                              function owner() public view returns (address);
                              function restake() public returns(uint256, uint256);
                              function unlock() external;
                              function lock() external;
                              function drain(
                                  address token,
                                  address payable destination,
                                  uint256 amount
                              ) external;
                              function slash(uint256 valPow, uint256 delegatedAmount, uint256 totalAmountToSlash) external returns (uint256);
                              function updateDelegation(bool delegation) external;
                              function migrateOut(address user, uint256 amount) external;
                              function migrateIn(address user, uint256 amount) external;
                          }
                          pragma solidity ^0.5.2;
                          contract Initializable {
                              bool inited = false;
                              modifier initializer() {
                                  require(!inited, "already inited");
                                  inited = true;
                                  _;
                              }
                              function _disableInitializer() internal {
                                  inited = true;
                              }
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity 0.5.17;
                          interface IERC20Permit {
                              function permit(
                                  address owner,
                                  address spender,
                                  uint256 value,
                                  uint256 deadline,
                                  uint8 v,
                                  bytes32 r,
                                  bytes32 s
                              ) external;
                              function nonces(address owner) external view returns (uint256);
                              // solhint-disable-next-line func-name-mixedcase
                              function DOMAIN_SEPARATOR() external view returns (bytes32);
                          }
                          pragma solidity ^0.5.2;
                          import {IGovernance} from "./IGovernance.sol";
                          contract Governable {
                              IGovernance public governance;
                              constructor(address _governance) public {
                                  governance = IGovernance(_governance);
                              }
                              modifier onlyGovernance() {
                                  _assertGovernance();
                                  _;
                              }
                              function _assertGovernance() private view {
                                  require(
                                      msg.sender == address(governance),
                                      "Only governance contract is authorized"
                                  );
                              }
                          }
                          pragma solidity ^0.5.2;
                          contract IWithdrawManager {
                              function createExitQueue(address token) external;
                              function verifyInclusion(
                                  bytes calldata data,
                                  uint8 offset,
                                  bool verifyTxInclusion
                              ) external view returns (uint256 age);
                              function addExitToQueue(
                                  address exitor,
                                  address childToken,
                                  address rootToken,
                                  uint256 exitAmountOrTokenId,
                                  bytes32 txHash,
                                  bool isRegularExit,
                                  uint256 priority
                              ) external;
                              function addInput(
                                  uint256 exitId,
                                  uint256 age,
                                  address utxoOwner,
                                  address token
                              ) external;
                              function challengeExit(
                                  uint256 exitId,
                                  uint256 inputId,
                                  bytes calldata challengeData,
                                  address adjudicatorPredicate
                              ) external;
                          }
                          pragma solidity ^0.5.2;
                          /**
                           * @title ERC20 interface
                           * @dev see https://eips.ethereum.org/EIPS/eip-20
                           */
                          interface IERC20 {
                              function transfer(address to, uint256 value) external returns (bool);
                              function approve(address spender, uint256 value) external returns (bool);
                              function transferFrom(address from, address to, uint256 value) external returns (bool);
                              function totalSupply() external view returns (uint256);
                              function balanceOf(address who) external view returns (uint256);
                              function allowance(address owner, address spender) external view returns (uint256);
                              event Transfer(address indexed from, address indexed to, uint256 value);
                              event Approval(address indexed owner, address indexed spender, uint256 value);
                          }
                          pragma solidity ^0.5.2;
                          /**
                           * @title SafeMath
                           * @dev Unsigned math operations with safety checks that revert on error
                           */
                          library SafeMath {
                              /**
                               * @dev Multiplies two unsigned integers, reverts on overflow.
                               */
                              function mul(uint256 a, uint256 b) internal pure returns (uint256) {
                                  // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
                                  // benefit is lost if 'b' is also tested.
                                  // See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522
                                  if (a == 0) {
                                      return 0;
                                  }
                                  uint256 c = a * b;
                                  require(c / a == b);
                                  return c;
                              }
                              /**
                               * @dev Integer division of two unsigned integers truncating the quotient, reverts on division by zero.
                               */
                              function div(uint256 a, uint256 b) internal pure returns (uint256) {
                                  // Solidity only automatically asserts when dividing by 0
                                  require(b > 0);
                                  uint256 c = a / b;
                                  // assert(a == b * c + a % b); // There is no case in which this doesn't hold
                                  return c;
                              }
                              /**
                               * @dev Subtracts two unsigned integers, reverts on overflow (i.e. if subtrahend is greater than minuend).
                               */
                              function sub(uint256 a, uint256 b) internal pure returns (uint256) {
                                  require(b <= a);
                                  uint256 c = a - b;
                                  return c;
                              }
                              /**
                               * @dev Adds two unsigned integers, reverts on overflow.
                               */
                              function add(uint256 a, uint256 b) internal pure returns (uint256) {
                                  uint256 c = a + b;
                                  require(c >= a);
                                  return c;
                              }
                              /**
                               * @dev Divides two unsigned integers and returns the remainder (unsigned integer modulo),
                               * reverts when dividing by zero.
                               */
                              function mod(uint256 a, uint256 b) internal pure returns (uint256) {
                                  require(b != 0);
                                  return a % b;
                              }
                          }
                          pragma solidity ^0.5.2;
                          /**
                           * @title Ownable
                           * @dev The Ownable contract has an owner address, and provides basic authorization control
                           * functions, this simplifies the implementation of "user permissions".
                           */
                          contract Ownable {
                              address private _owner;
                              event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
                              /**
                               * @dev The Ownable constructor sets the original `owner` of the contract to the sender
                               * account.
                               */
                              constructor () internal {
                                  _owner = msg.sender;
                                  emit OwnershipTransferred(address(0), _owner);
                              }
                              /**
                               * @return the address of the owner.
                               */
                              function owner() public view returns (address) {
                                  return _owner;
                              }
                              /**
                               * @dev Throws if called by any account other than the owner.
                               */
                              modifier onlyOwner() {
                                  require(isOwner());
                                  _;
                              }
                              /**
                               * @return true if `msg.sender` is the owner of the contract.
                               */
                              function isOwner() public view returns (bool) {
                                  return msg.sender == _owner;
                              }
                              /**
                               * @dev Allows the current owner to relinquish control of the contract.
                               * It will not be possible to call the functions with the `onlyOwner`
                               * modifier anymore.
                               * @notice Renouncing ownership will leave the contract without an owner,
                               * thereby removing any functionality that is only available to the owner.
                               */
                              function renounceOwnership() public onlyOwner {
                                  emit OwnershipTransferred(_owner, address(0));
                                  _owner = address(0);
                              }
                              /**
                               * @dev Allows the current owner to transfer control of the contract to a newOwner.
                               * @param newOwner The address to transfer ownership to.
                               */
                              function transferOwnership(address newOwner) public onlyOwner {
                                  _transferOwnership(newOwner);
                              }
                              /**
                               * @dev Transfers control of the contract to a newOwner.
                               * @param newOwner The address to transfer ownership to.
                               */
                              function _transferOwnership(address newOwner) internal {
                                  require(newOwner != address(0));
                                  emit OwnershipTransferred(_owner, newOwner);
                                  _owner = newOwner;
                              }
                          }
                          pragma solidity ^0.5.2;
                          contract Lockable {
                              bool public locked;
                              modifier onlyWhenUnlocked() {
                                  _assertUnlocked();
                                  _;
                              }
                              function _assertUnlocked() private view {
                                  require(!locked, "locked");
                              }
                              function lock() public {
                                  locked = true;
                              }
                              function unlock() public {
                                  locked = false;
                              }
                          }
                          pragma solidity ^0.5.2;
                          interface IGovernance {
                              function update(address target, bytes calldata data) external;
                          }
                          

                          File 5 of 6: StakeManagerProxy
                          // File: openzeppelin-solidity/contracts/ownership/Ownable.sol
                          
                          pragma solidity ^0.5.2;
                          
                          /**
                           * @title Ownable
                           * @dev The Ownable contract has an owner address, and provides basic authorization control
                           * functions, this simplifies the implementation of "user permissions".
                           */
                          contract Ownable {
                              address private _owner;
                          
                              event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
                          
                              /**
                               * @dev The Ownable constructor sets the original `owner` of the contract to the sender
                               * account.
                               */
                              constructor () internal {
                                  _owner = msg.sender;
                                  emit OwnershipTransferred(address(0), _owner);
                              }
                          
                              /**
                               * @return the address of the owner.
                               */
                              function owner() public view returns (address) {
                                  return _owner;
                              }
                          
                              /**
                               * @dev Throws if called by any account other than the owner.
                               */
                              modifier onlyOwner() {
                                  require(isOwner());
                                  _;
                              }
                          
                              /**
                               * @return true if `msg.sender` is the owner of the contract.
                               */
                              function isOwner() public view returns (bool) {
                                  return msg.sender == _owner;
                              }
                          
                              /**
                               * @dev Allows the current owner to relinquish control of the contract.
                               * It will not be possible to call the functions with the `onlyOwner`
                               * modifier anymore.
                               * @notice Renouncing ownership will leave the contract without an owner,
                               * thereby removing any functionality that is only available to the owner.
                               */
                              function renounceOwnership() public onlyOwner {
                                  emit OwnershipTransferred(_owner, address(0));
                                  _owner = address(0);
                              }
                          
                              /**
                               * @dev Allows the current owner to transfer control of the contract to a newOwner.
                               * @param newOwner The address to transfer ownership to.
                               */
                              function transferOwnership(address newOwner) public onlyOwner {
                                  _transferOwnership(newOwner);
                              }
                          
                              /**
                               * @dev Transfers control of the contract to a newOwner.
                               * @param newOwner The address to transfer ownership to.
                               */
                              function _transferOwnership(address newOwner) internal {
                                  require(newOwner != address(0));
                                  emit OwnershipTransferred(_owner, newOwner);
                                  _owner = newOwner;
                              }
                          }
                          // File: contracts/common/misc/ERCProxy.sol
                          
                          /*
                           * SPDX-License-Identitifer:    MIT
                           */
                          
                          pragma solidity ^0.5.2;
                          
                          // See https://github.com/ethereum/EIPs/blob/master/EIPS/eip-897.md
                          
                          interface ERCProxy {
                              function proxyType() external pure returns (uint256 proxyTypeId);
                              function implementation() external view returns (address codeAddr);
                          }
                          
                          // File: contracts/common/misc/DelegateProxy.sol
                          
                          pragma solidity ^0.5.2;
                          
                          
                          
                          contract DelegateProxy is ERCProxy {
                              function proxyType() external pure returns (uint256 proxyTypeId) {
                                  // Upgradeable proxy
                                  proxyTypeId = 2;
                              }
                          
                              function implementation() external view returns (address);
                          
                              function delegatedFwd(address _dst, bytes memory _calldata) internal {
                                  // solium-disable-next-line security/no-inline-assembly
                                  assembly {
                                      let result := delegatecall(
                                          sub(gas, 10000),
                                          _dst,
                                          add(_calldata, 0x20),
                                          mload(_calldata),
                                          0,
                                          0
                                      )
                                      let size := returndatasize
                          
                                      let ptr := mload(0x40)
                                      returndatacopy(ptr, 0, size)
                          
                                      // revert instead of invalid() bc if the underlying call failed with invalid() it already wasted gas.
                                      // if the call returned error data, forward it
                                      switch result
                                          case 0 {
                                              revert(ptr, size)
                                          }
                                          default {
                                              return(ptr, size)
                                          }
                                  }
                              }
                          }
                          
                          // File: contracts/common/misc/UpgradableProxy.sol
                          
                          pragma solidity ^0.5.2;
                          
                          
                          contract UpgradableProxy is DelegateProxy {
                              event ProxyUpdated(address indexed _new, address indexed _old);
                              event OwnerUpdate(address _new, address _old);
                          
                              bytes32 constant IMPLEMENTATION_SLOT = keccak256("matic.network.proxy.implementation");
                              bytes32 constant OWNER_SLOT = keccak256("matic.network.proxy.owner");
                          
                              constructor(address _proxyTo) public {
                                  setOwner(msg.sender);
                                  setImplementation(_proxyTo);
                              }
                          
                              function() external payable {
                                  // require(currentContract != 0, "If app code has not been set yet, do not call");
                                  // Todo: filter out some calls or handle in the end fallback
                                  delegatedFwd(loadImplementation(), msg.data);
                              }
                          
                              modifier onlyProxyOwner() {
                                  require(loadOwner() == msg.sender, "NOT_OWNER");
                                  _;
                              }
                          
                              function owner() external view returns(address) {
                                  return loadOwner();
                              }
                          
                              function loadOwner() internal view returns(address) {
                                  address _owner;
                                  bytes32 position = OWNER_SLOT;
                                  assembly {
                                      _owner := sload(position)
                                  }
                                  return _owner;
                              }
                          
                              function implementation() external view returns (address) {
                                  return loadImplementation();
                              }
                          
                              function loadImplementation() internal view returns(address) {
                                  address _impl;
                                  bytes32 position = IMPLEMENTATION_SLOT;
                                  assembly {
                                      _impl := sload(position)
                                  }
                                  return _impl;
                              }
                          
                              function transferOwnership(address newOwner) public onlyProxyOwner {
                                  require(newOwner != address(0), "ZERO_ADDRESS");
                                  emit OwnerUpdate(newOwner, loadOwner());
                                  setOwner(newOwner);
                              }
                          
                              function setOwner(address newOwner) private {
                                  bytes32 position = OWNER_SLOT;
                                  assembly {
                                      sstore(position, newOwner)
                                  }
                              }
                          
                              function updateImplementation(address _newProxyTo) public onlyProxyOwner {
                                  require(_newProxyTo != address(0x0), "INVALID_PROXY_ADDRESS");
                                  require(isContract(_newProxyTo), "DESTINATION_ADDRESS_IS_NOT_A_CONTRACT");
                          
                                  emit ProxyUpdated(_newProxyTo, loadImplementation());
                                  
                                  setImplementation(_newProxyTo);
                              }
                          
                              function updateAndCall(address _newProxyTo, bytes memory data) payable public onlyProxyOwner {
                                  updateImplementation(_newProxyTo);
                          
                                  (bool success, bytes memory returnData) = address(this).call.value(msg.value)(data);
                                  require(success, string(returnData));
                              }
                          
                              function setImplementation(address _newProxyTo) private {
                                  bytes32 position = IMPLEMENTATION_SLOT;
                                  assembly {
                                      sstore(position, _newProxyTo)
                                  }
                              }
                              
                              function isContract(address _target) internal view returns (bool) {
                                  if (_target == address(0)) {
                                      return false;
                                  }
                          
                                  uint256 size;
                                  assembly {
                                      size := extcodesize(_target)
                                  }
                                  return size > 0;
                              }
                          }
                          
                          // File: contracts/staking/stakeManager/StakeManagerProxy.sol
                          
                          pragma solidity ^0.5.2;
                          
                          
                          contract StakeManagerProxy is UpgradableProxy {
                              constructor(address _proxyTo) public UpgradableProxy(_proxyTo) {}
                          }

                          File 6 of 6: StakeManager
                          pragma solidity 0.5.17;
                          import {IERC20} from "openzeppelin-solidity/contracts/token/ERC20/IERC20.sol";
                          import {Math} from "openzeppelin-solidity/contracts/math/Math.sol";
                          import {SafeMath} from "openzeppelin-solidity/contracts/math/SafeMath.sol";
                          import {ECVerify} from "../../common/lib/ECVerify.sol";
                          import {Merkle} from "../../common/lib/Merkle.sol";
                          import {GovernanceLockable} from "../../common/mixin/GovernanceLockable.sol";
                          import {DelegateProxyForwarder} from "../../common/misc/DelegateProxyForwarder.sol";
                          import {Registry} from "../../common/Registry.sol";
                          import {IStakeManager} from "./IStakeManager.sol";
                          import {IValidatorShare} from "../validatorShare/IValidatorShare.sol";
                          import {ValidatorShare} from "../validatorShare/ValidatorShare.sol";
                          import {StakingInfo} from "../StakingInfo.sol";
                          import {StakingNFT} from "./StakingNFT.sol";
                          import {ValidatorShareFactory} from "../validatorShare/ValidatorShareFactory.sol";
                          import {StakeManagerStorage} from "./StakeManagerStorage.sol";
                          import {StakeManagerStorageExtension} from "./StakeManagerStorageExtension.sol";
                          import {IGovernance} from "../../common/governance/IGovernance.sol";
                          import {Initializable} from "../../common/mixin/Initializable.sol";
                          import {StakeManagerExtension} from "./StakeManagerExtension.sol";
                          import {IPolygonMigration} from "../../common/misc/IPolygonMigration.sol";
                          contract StakeManager is
                              StakeManagerStorage,
                              Initializable,
                              IStakeManager,
                              DelegateProxyForwarder,
                              StakeManagerStorageExtension
                          {
                              using SafeMath for uint256;
                              using Merkle for bytes32;
                              struct UnsignedValidatorsContext {
                                  uint256 unsignedValidatorIndex;
                                  uint256 validatorIndex;
                                  uint256[] unsignedValidators;
                                  address[] validators;
                                  uint256 totalValidators;
                              }
                              struct UnstakedValidatorsContext {
                                  uint256 deactivationEpoch;
                                  uint256[] deactivatedValidators;
                                  uint256 validatorIndex;
                              }
                              modifier onlyStaker(uint256 validatorId) {
                                  _assertStaker(validatorId);
                                  _;
                              }
                              function _assertStaker(uint256 validatorId) private view {
                                  require(NFTContract.ownerOf(validatorId) == msg.sender);
                              }
                              modifier onlyDelegation(uint256 validatorId) {
                                  _assertDelegation(validatorId);
                                  _;
                              }
                              function _assertDelegation(uint256 validatorId) private view {
                                  require(validators[validatorId].contractAddress == msg.sender, "Invalid contract address");
                              }
                              constructor() public GovernanceLockable(address(0x0)) {
                                  _disableInitializer();
                              }
                              function initialize(
                                  address _registry,
                                  address _rootchain,
                                  address _token,
                                  address _NFTContract,
                                  address _stakingLogger,
                                  address _validatorShareFactory,
                                  address _governance,
                                  address _owner,
                                  address _extensionCode
                              ) external initializer {
                                  require(isContract(_extensionCode), "auction impl incorrect");
                                  extensionCode = _extensionCode;
                                  governance = IGovernance(_governance);
                                  registry = _registry;
                                  rootChain = _rootchain;
                                  token = IERC20(_token);
                                  NFTContract = StakingNFT(_NFTContract);
                                  logger = StakingInfo(_stakingLogger);
                                  validatorShareFactory = ValidatorShareFactory(_validatorShareFactory);
                                  _transferOwnership(_owner);
                                  WITHDRAWAL_DELAY = (2**13); // unit: epoch
                                  currentEpoch = 1;
                                  dynasty = 886; // unit: epoch 50 days
                                  CHECKPOINT_REWARD = 20188 * (10**18); // update via governance
                                  minDeposit = (10**18); // in ERC20 token
                                  minHeimdallFee = (10**18); // in ERC20 token
                                  checkPointBlockInterval = 1024;
                                  signerUpdateLimit = 100;
                                  validatorThreshold = 7; //128
                                  NFTCounter = 1;
                                  auctionPeriod = (2**13) / 4; // 1 week in epochs
                                  proposerBonus = 10; // 10 % of total rewards
                                  delegationEnabled = true;
                              }
                              function reinitialize(
                                  address _NFTContract,
                                  address _stakingLogger,
                                  address _validatorShareFactory,
                                  address _extensionCode
                              ) external onlyGovernance {
                                  require(isContract(_extensionCode));
                                  eventsHub = address(0x0);
                                  extensionCode = _extensionCode;
                                  NFTContract = StakingNFT(_NFTContract);
                                  logger = StakingInfo(_stakingLogger);
                                  validatorShareFactory = ValidatorShareFactory(_validatorShareFactory);
                              }
                              function initializePOL(
                                  address _tokenNew,
                                  address _migration
                              ) external onlyGovernance {
                                  tokenMatic = IERC20(token);
                                  token = IERC20(_tokenNew);
                                  migration = IPolygonMigration(_migration);
                                  _convertMaticToPOL(tokenMatic.balanceOf(address(this)));
                              }
                              function isOwner() public view returns (bool) {
                                  address _owner;
                                  bytes32 position = keccak256("matic.network.proxy.owner");
                                  assembly {
                                      _owner := sload(position)
                                  }
                                  return msg.sender == _owner;
                              }
                              /**
                                  Public View Methods
                               */
                              function getRegistry() public view returns (address) {
                                  return registry;
                              }
                              /**
                                  @dev Owner of validator slot NFT
                               */
                              function ownerOf(uint256 tokenId) public view returns (address) {
                                  return NFTContract.ownerOf(tokenId);
                              }
                              function epoch() public view returns (uint256) {
                                  return currentEpoch;
                              }
                              function withdrawalDelay() public view returns (uint256) {
                                  return WITHDRAWAL_DELAY;
                              }
                              function validatorStake(uint256 validatorId) public view returns (uint256) {
                                  return validators[validatorId].amount;
                              }
                              function getValidatorId(address user) public view returns (uint256) {
                                  return NFTContract.tokenOfOwnerByIndex(user, 0);
                              }
                              function delegatedAmount(uint256 validatorId) public view returns (uint256) {
                                  return validators[validatorId].delegatedAmount;
                              }
                              function delegatorsReward(uint256 validatorId) public view returns (uint256) {
                                  uint256 _delegatorsReward;
                                  if (validators[validatorId].deactivationEpoch == 0) {
                                      (, _delegatorsReward) = _evaluateValidatorAndDelegationReward(validatorId);
                                  }
                                  return validators[validatorId].delegatorsReward.add(_delegatorsReward).sub(INITIALIZED_AMOUNT);
                              }
                              function validatorReward(uint256 validatorId) public view returns (uint256) {
                                  uint256 _validatorReward;
                                  if (validators[validatorId].deactivationEpoch == 0) {
                                      (_validatorReward, ) = _evaluateValidatorAndDelegationReward(validatorId);
                                  }
                                  return validators[validatorId].reward.add(_validatorReward).sub(INITIALIZED_AMOUNT);
                              }
                              function currentValidatorSetSize() public view returns (uint256) {
                                  return validatorState.stakerCount;
                              }
                              function currentValidatorSetTotalStake() public view returns (uint256) {
                                  return validatorState.amount;
                              }
                              function getValidatorContract(uint256 validatorId) public view returns (address) {
                                  return validators[validatorId].contractAddress;
                              }
                              function isValidator(uint256 validatorId) public view returns (bool) {
                                  return
                                      _isValidator(
                                          validators[validatorId].status,
                                          validators[validatorId].amount,
                                          validators[validatorId].deactivationEpoch,
                                          currentEpoch
                                      );
                              }
                              /**
                                  Governance Methods
                               */
                              function setDelegationEnabled(bool enabled) public onlyGovernance {
                                  delegationEnabled = enabled;
                              }
                              // Housekeeping function. @todo remove later
                              function forceUnstake(uint256 validatorId) external onlyGovernance {
                                  _unstake(validatorId, currentEpoch, false);
                              }
                              function forceUnstakePOL(uint256 validatorId) external onlyGovernance {
                                  _unstake(validatorId, currentEpoch, true);
                              }
                              function setCurrentEpoch(uint256 _currentEpoch) external onlyGovernance {
                                  currentEpoch = _currentEpoch;
                              }
                              function setStakingToken(address _token) public onlyGovernance {
                                  require(_token != address(0x0));
                                  token = IERC20(_token);
                              }
                              /**
                               * @dev Change the number of validators required to allow a passed header root
                               */
                              function updateValidatorThreshold(uint256 newThreshold) public onlyGovernance {
                                  require(newThreshold != 0);
                                  logger.logThresholdChange(newThreshold, validatorThreshold);
                                  validatorThreshold = newThreshold;
                              }
                              function updateCheckPointBlockInterval(uint256 _blocks) public onlyGovernance {
                                  require(_blocks != 0);
                                  checkPointBlockInterval = _blocks;
                              }
                              function updateCheckpointReward(uint256 newReward) public onlyGovernance {
                                  require(newReward != 0);
                                  logger.logRewardUpdate(newReward, CHECKPOINT_REWARD);
                                  CHECKPOINT_REWARD = newReward;
                              }
                              function updateCheckpointRewardParams(
                                  uint256 _rewardDecreasePerCheckpoint,
                                  uint256 _maxRewardedCheckpoints,
                                  uint256 _checkpointRewardDelta
                              ) public onlyGovernance {
                                  delegatedFwd(
                                      extensionCode,
                                      abi.encodeWithSelector(
                                          StakeManagerExtension(extensionCode).updateCheckpointRewardParams.selector,
                                          _rewardDecreasePerCheckpoint,
                                          _maxRewardedCheckpoints,
                                          _checkpointRewardDelta
                                      )
                                  );
                              }
                              // New implementation upgrade
                              function migrateValidatorsData(uint256 validatorIdFrom, uint256 validatorIdTo) public onlyOwner {
                                  delegatedFwd(
                                      extensionCode,
                                      abi.encodeWithSelector(
                                          StakeManagerExtension(extensionCode).migrateValidatorsData.selector,
                                          validatorIdFrom,
                                          validatorIdTo
                                      )
                                  );
                              }
                              function insertSigners(address[] memory _signers) public onlyOwner {
                                  signers = _signers;
                              }
                              /**
                                  @dev Users must exit before this update or all funds may get lost
                               */
                              function updateValidatorContractAddress(uint256 validatorId, address newContractAddress) public onlyGovernance {
                                  require(IValidatorShare(newContractAddress).owner() == address(this));
                                  validators[validatorId].contractAddress = newContractAddress;
                              }
                              function updateDynastyValue(uint256 newDynasty) public onlyGovernance {
                                  require(newDynasty > 0);
                                  logger.logDynastyValueChange(newDynasty, dynasty);
                                  dynasty = newDynasty;
                                  WITHDRAWAL_DELAY = newDynasty;
                                  auctionPeriod = newDynasty.div(4);
                                  replacementCoolDown = currentEpoch.add(auctionPeriod);
                              }
                              // Housekeeping function. @todo remove later
                              function stopAuctions(uint256 forNCheckpoints) public onlyGovernance {
                                  replacementCoolDown = currentEpoch.add(forNCheckpoints);
                              }
                              function updateProposerBonus(uint256 newProposerBonus) public onlyGovernance {
                                  logger.logProposerBonusChange(newProposerBonus, proposerBonus);
                                  require(newProposerBonus <= MAX_PROPOSER_BONUS, "too big");
                                  proposerBonus = newProposerBonus;
                              }
                              function updateSignerUpdateLimit(uint256 _limit) public onlyGovernance {
                                  signerUpdateLimit = _limit;
                              }
                              function updateMinAmounts(uint256 _minDeposit, uint256 _minHeimdallFee) public onlyGovernance {
                                  minDeposit = _minDeposit;
                                  minHeimdallFee = _minHeimdallFee;
                              }
                              /**
                                  Public Methods
                               */
                              function topUpForFee(address user, uint256 heimdallFee) public onlyWhenUnlocked {
                                  _transferAndTopUp(user, msg.sender, heimdallFee, 0, true);
                              }
                              function claimFee(uint256 accumFeeAmount, uint256 index, bytes memory proof) public {
                                  require(keccak256(abi.encode(msg.sender, accumFeeAmount)).checkMembership(index, accountStateRoot, proof), "Wrong acc proof");
                                  uint256 withdrawAmount = accumFeeAmount.sub(userFeeExit[msg.sender]);
                                  totalHeimdallFee = totalHeimdallFee.sub(withdrawAmount);
                                  logger.logClaimFee(msg.sender, withdrawAmount);
                                  userFeeExit[msg.sender] = accumFeeAmount;
                                  _transferToken(msg.sender, withdrawAmount, true);
                              }
                              function totalStakedFor(address user) external view returns (uint256) {
                                  if (user == address(0x0) || NFTContract.balanceOf(user) == 0) {
                                      return 0;
                                  }
                                  return validators[NFTContract.tokenOfOwnerByIndex(user, 0)].amount;
                              }
                              function startAuction(
                                  uint256 validatorId,
                                  uint256 amount,
                                  bool _acceptDelegation,
                                  bytes calldata _signerPubkey
                              ) external onlyWhenUnlocked {
                                  delegatedFwd(
                                      extensionCode,
                                      abi.encodeWithSelector(
                                          StakeManagerExtension(extensionCode).startAuction.selector,
                                          validatorId,
                                          amount,
                                          _acceptDelegation,
                                          _signerPubkey
                                      )
                                  );
                              }
                              function confirmAuctionBid(
                                  uint256 validatorId,
                                  uint256 heimdallFee /** for new validator */
                              ) external onlyWhenUnlocked {
                                  delegatedFwd(
                                      extensionCode,
                                      abi.encodeWithSelector(
                                          StakeManagerExtension(extensionCode).confirmAuctionBid.selector,
                                          validatorId,
                                          heimdallFee,
                                          address(this)
                                      )
                                  );
                              }
                              function dethroneAndStake(
                                  address auctionUser,
                                  uint256 heimdallFee,
                                  uint256 validatorId,
                                  uint256 auctionAmount,
                                  bool acceptDelegation,
                                  bytes calldata signerPubkey
                              ) external {
                                  require(msg.sender == address(this), "not allowed");
                                  // dethrone
                                  _transferAndTopUp(auctionUser, auctionUser, heimdallFee, 0, true);
                                  _unstake(validatorId, currentEpoch, true);
                                  uint256 newValidatorId = _stakeFor(auctionUser, auctionAmount, acceptDelegation, signerPubkey);
                                  logger.logConfirmAuction(newValidatorId, validatorId, auctionAmount);
                              }
                              function unstake(uint256 validatorId) external onlyStaker(validatorId) {
                                  _unstakeValidator(validatorId, false);
                              }
                              function unstakePOL(uint256 validatorId) external onlyStaker(validatorId) {
                                  _unstakeValidator(validatorId, true);
                              }
                              function _unstakeValidator(uint256 validatorId, bool pol) internal {
                                  require(validatorAuction[validatorId].amount == 0);
                                  Status status = validators[validatorId].status;
                                  require(
                                      validators[validatorId].activationEpoch > 0 &&
                                          validators[validatorId].deactivationEpoch == 0 &&
                                          (status == Status.Active || status == Status.Locked)
                                  );
                                  uint256 exitEpoch = currentEpoch.add(1); // notice period
                                  _unstake(validatorId, exitEpoch, pol);
                              }
                              function transferFunds(uint256 validatorId, uint256 amount, address delegator) external returns (bool) {
                                  return _transferFunds(validatorId, amount, delegator, false);
                              }
                              function transferFundsPOL(uint256 validatorId, uint256 amount, address delegator) external returns (bool) {
                                  return _transferFunds(validatorId, amount, delegator, true);
                              }
                              function _transferFunds(uint256 validatorId, uint256 amount, address delegator, bool pol) internal returns (bool) {
                                  require(validators[validatorId].contractAddress == msg.sender || Registry(registry).getSlashingManagerAddress() == msg.sender, "not allowed");
                                  if (!pol) _convertPOLToMatic(amount);
                                  IERC20 token_ = _getToken(pol);
                                  return token_.transfer(delegator, amount);
                              }
                              function delegationDeposit(uint256 validatorId, uint256 amount, address delegator) external onlyDelegation(validatorId) returns (bool) {
                                  return _delegationDeposit(amount, delegator, false);
                              }
                              function delegationDepositPOL(uint256 validatorId, uint256 amount, address delegator) external onlyDelegation(validatorId) returns (bool) {
                                  return _delegationDeposit(amount, delegator, true);
                              }
                              function _delegationDeposit(uint256 amount, address delegator, bool pol) internal returns (bool) {
                                  IERC20 token_ = _getToken(pol);
                                  bool result = token_.transferFrom(delegator, address(this), amount);
                                  if (!pol) _convertMaticToPOL(amount);
                                  return result;
                              }
                              function stakeFor(address user, uint256 amount, uint256 heimdallFee, bool acceptDelegation, bytes memory signerPubkey) public onlyWhenUnlocked {
                                  _stakeFor(user, amount, heimdallFee, acceptDelegation, signerPubkey, false);
                              }
                              function stakeForPOL(address user, uint256 amount, uint256 heimdallFee, bool acceptDelegation, bytes memory signerPubkey) public onlyWhenUnlocked {
                                  _stakeFor(user, amount, heimdallFee, acceptDelegation, signerPubkey, true);
                              }
                              function _stakeFor(address user, uint256 amount, uint256 heimdallFee, bool acceptDelegation, bytes memory signerPubkey, bool pol) internal {
                                  require(currentValidatorSetSize() < validatorThreshold, "no more slots");
                                  require(amount >= minDeposit, "not enough deposit");
                                  _transferAndTopUp(user, msg.sender, heimdallFee, amount, pol);
                                  _stakeFor(user, amount, acceptDelegation, signerPubkey);
                              }
                              function unstakeClaim(uint256 validatorId) public onlyStaker(validatorId) {
                                  _unstakeClaim(validatorId, false);
                              }
                              function unstakeClaimPOL(uint256 validatorId) public onlyStaker(validatorId) {
                                  _unstakeClaim(validatorId, true);
                              }
                              function _unstakeClaim(uint256 validatorId, bool pol) internal {
                                  uint256 deactivationEpoch = validators[validatorId].deactivationEpoch;
                                  // can only claim stake back after WITHDRAWAL_DELAY
                                  require(
                                      deactivationEpoch > 0 &&
                                          deactivationEpoch.add(WITHDRAWAL_DELAY) <= currentEpoch &&
                                          validators[validatorId].status != Status.Unstaked
                                  );
                                  uint256 amount = validators[validatorId].amount;
                                  uint256 newTotalStaked = totalStaked.sub(amount);
                                  totalStaked = newTotalStaked;
                                  // claim last checkpoint reward if it was signed by validator
                                  _liquidateRewards(validatorId, msg.sender, pol);
                                  NFTContract.burn(validatorId);
                                  validators[validatorId].amount = 0;
                                  validators[validatorId].jailTime = 0;
                                  validators[validatorId].signer = address(0);
                                  signerToValidator[validators[validatorId].signer] = INCORRECT_VALIDATOR_ID;
                                  validators[validatorId].status = Status.Unstaked;
                                  _transferToken(msg.sender, amount, pol);
                                  logger.logUnstaked(msg.sender, validatorId, amount, newTotalStaked);
                              }
                              function restake(uint256 validatorId, uint256 amount, bool stakeRewards) public onlyWhenUnlocked onlyStaker(validatorId) {
                                  _restake(validatorId, amount, stakeRewards, false);
                              }
                              function restakePOL(uint256 validatorId, uint256 amount, bool stakeRewards) public onlyWhenUnlocked onlyStaker(validatorId) {
                                  _restake(validatorId, amount, stakeRewards, true);
                              }
                              function _restake(uint256 validatorId, uint256 amount, bool stakeRewards, bool pol) internal {
                                  require(validators[validatorId].deactivationEpoch == 0, "No restaking");
                                  if (amount > 0) {
                                      _transferTokenFrom(msg.sender, address(this), amount, pol);
                                  }
                                  _updateRewards(validatorId);
                                  if (stakeRewards) {
                                      amount = amount.add(validators[validatorId].reward).sub(INITIALIZED_AMOUNT);
                                      validators[validatorId].reward = INITIALIZED_AMOUNT;
                                  }
                                  uint256 newTotalStaked = totalStaked.add(amount);
                                  totalStaked = newTotalStaked;
                                  validators[validatorId].amount = validators[validatorId].amount.add(amount);
                                  updateTimeline(int256(amount), 0, 0);
                                  logger.logStakeUpdate(validatorId);
                                  logger.logRestaked(validatorId, validators[validatorId].amount, newTotalStaked);
                              }
                              function withdrawRewards(uint256 validatorId) public onlyStaker(validatorId) {
                                  _withdrawRewards(validatorId, false);
                              }
                              function withdrawRewardsPOL(uint256 validatorId) public onlyStaker(validatorId) {
                                  _withdrawRewards(validatorId, true);
                              }
                              function _withdrawRewards(uint256 validatorId, bool pol) internal {
                                  _updateRewards(validatorId);
                                  _liquidateRewards(validatorId, msg.sender, pol);
                              }
                              function migrateDelegation(
                                  uint256 fromValidatorId,
                                  uint256 toValidatorId,
                                  uint256 amount
                              ) public {
                                  // allow to move to any non-foundation node
                                  require(toValidatorId > 7, "Invalid migration");
                                  IValidatorShare(validators[fromValidatorId].contractAddress).migrateOut(msg.sender, amount);
                                  IValidatorShare(validators[toValidatorId].contractAddress).migrateIn(msg.sender, amount);
                              }
                              function updateValidatorState(uint256 validatorId, int256 amount) public onlyDelegation(validatorId) {
                                  if (amount > 0) {
                                      // deposit during shares purchase
                                      require(delegationEnabled, "Delegation is disabled");
                                  }
                                  uint256 deactivationEpoch = validators[validatorId].deactivationEpoch;
                                  if (deactivationEpoch == 0) { // modify timeline only if validator didn't unstake
                                      updateTimeline(amount, 0, 0);
                                  } else if (deactivationEpoch > currentEpoch) { // validator just unstaked, need to wait till next checkpoint
                                      revert("unstaking");
                                  }
                                  
                                  if (amount >= 0) {
                                      increaseValidatorDelegatedAmount(validatorId, uint256(amount));
                                  } else {
                                      decreaseValidatorDelegatedAmount(validatorId, uint256(amount * -1));
                                  }
                              }
                              function increaseValidatorDelegatedAmount(uint256 validatorId, uint256 amount) private {
                                  validators[validatorId].delegatedAmount = validators[validatorId].delegatedAmount.add(amount);
                              }
                              function decreaseValidatorDelegatedAmount(uint256 validatorId, uint256 amount) public onlyDelegation(validatorId) {
                                  validators[validatorId].delegatedAmount = validators[validatorId].delegatedAmount.sub(amount);
                              }
                              function updateSigner(uint256 validatorId, bytes memory signerPubkey) public onlyStaker(validatorId) {
                                  address signer = _getAndAssertSigner(signerPubkey);
                                  uint256 _currentEpoch = currentEpoch;
                                  require(_currentEpoch >= latestSignerUpdateEpoch[validatorId].add(signerUpdateLimit), "Not allowed");
                                  address currentSigner = validators[validatorId].signer;
                                  // update signer event
                                  logger.logSignerChange(validatorId, currentSigner, signer, signerPubkey);
                                  
                                  if (validators[validatorId].deactivationEpoch == 0) { 
                                      // didn't unstake, swap signer in the list
                                      _removeSigner(currentSigner);
                                      _insertSigner(signer);
                                  }
                                  signerToValidator[currentSigner] = INCORRECT_VALIDATOR_ID;
                                  signerToValidator[signer] = validatorId;
                                  validators[validatorId].signer = signer;
                                  // reset update time to current time
                                  latestSignerUpdateEpoch[validatorId] = _currentEpoch;
                              }
                              function checkSignatures(
                                  uint256 blockInterval,
                                  bytes32 voteHash,
                                  bytes32 stateRoot,
                                  address proposer,
                                  uint256[3][] calldata sigs
                              ) external onlyRootChain returns (uint256) {
                                  uint256 _currentEpoch = currentEpoch;
                                  uint256 signedStakePower;
                                  address lastAdd;
                                  uint256 totalStakers = validatorState.stakerCount;
                                  UnsignedValidatorsContext memory unsignedCtx;
                                  unsignedCtx.unsignedValidators = new uint256[](signers.length + totalStakers);
                                  unsignedCtx.validators = signers;
                                  unsignedCtx.validatorIndex = 0;
                                  unsignedCtx.totalValidators = signers.length;
                                  UnstakedValidatorsContext memory unstakeCtx;
                                  unstakeCtx.deactivatedValidators = new uint256[](signers.length + totalStakers);
                                  for (uint256 i = 0; i < sigs.length; ++i) {
                                      address signer = ECVerify.ecrecovery(voteHash, sigs[i]);
                                      if (signer == lastAdd) {
                                          // if signer signs twice, just skip this signature
                                          continue;
                                      }
                                      if (signer < lastAdd) {
                                          // if signatures are out of order - break out, it is not possible to keep track of unsigned validators
                                          break;
                                      }
                                      uint256 validatorId = signerToValidator[signer];
                                      uint256 amount = validators[validatorId].amount;
                                      Status status = validators[validatorId].status;
                                      unstakeCtx.deactivationEpoch = validators[validatorId].deactivationEpoch;
                                      if (_isValidator(status, amount, unstakeCtx.deactivationEpoch, _currentEpoch)) {
                                          lastAdd = signer;
                                          signedStakePower = signedStakePower.add(validators[validatorId].delegatedAmount).add(amount);
                                          if (unstakeCtx.deactivationEpoch != 0) {
                                              // this validator not a part of signers list anymore
                                              unstakeCtx.deactivatedValidators[unstakeCtx.validatorIndex] = validatorId;
                                              unstakeCtx.validatorIndex++;
                                          } else {
                                              unsignedCtx = _fillUnsignedValidators(unsignedCtx, signer);
                                          }
                                      } else if (status == Status.Locked) {
                                          // TODO fix double unsignedValidators appearance
                                          // make sure that jailed validator doesn't get his rewards too
                                          unsignedCtx.unsignedValidators[unsignedCtx.unsignedValidatorIndex] = validatorId;
                                          unsignedCtx.unsignedValidatorIndex++;
                                          unsignedCtx.validatorIndex++;
                                      }
                                  }
                                  // find the rest of validators without signature
                                  unsignedCtx = _fillUnsignedValidators(unsignedCtx, address(0));
                                  return
                                      _increaseRewardAndAssertConsensus(
                                          blockInterval,
                                          proposer,
                                          signedStakePower,
                                          stateRoot,
                                          unsignedCtx.unsignedValidators,
                                          unsignedCtx.unsignedValidatorIndex,
                                          unstakeCtx.deactivatedValidators,
                                          unstakeCtx.validatorIndex
                                      );
                              }
                              function updateCommissionRate(uint256 validatorId, uint256 newCommissionRate) external onlyStaker(validatorId) {
                                  _updateRewards(validatorId);
                                  delegatedFwd(
                                      extensionCode,
                                      abi.encodeWithSelector(
                                          StakeManagerExtension(extensionCode).updateCommissionRate.selector,
                                          validatorId,
                                          newCommissionRate
                                      )
                                  );
                              }
                              function withdrawDelegatorsReward(uint256 validatorId) public onlyDelegation(validatorId) returns (uint256) {
                                  _updateRewards(validatorId);
                                  uint256 totalReward = validators[validatorId].delegatorsReward.sub(INITIALIZED_AMOUNT);
                                  validators[validatorId].delegatorsReward = INITIALIZED_AMOUNT;
                                  return totalReward;
                              }
                              function slash(bytes calldata _slashingInfoList) external returns (uint256) {
                                  revert();
                              }
                              function unjail(uint256 validatorId) public onlyStaker(validatorId) {
                                  require(validators[validatorId].status == Status.Locked, "Not jailed");
                                  require(validators[validatorId].deactivationEpoch == 0, "Already unstaking");
                                  uint256 _currentEpoch = currentEpoch;
                                  require(validators[validatorId].jailTime <= _currentEpoch, "Incomplete jail period");
                                  uint256 amount = validators[validatorId].amount;
                                  require(amount >= minDeposit);
                                  address delegationContract = validators[validatorId].contractAddress;
                                  if (delegationContract != address(0x0)) {
                                      IValidatorShare(delegationContract).unlock();
                                  }
                                  // undo timeline so that validator is normal validator
                                  updateTimeline(int256(amount.add(validators[validatorId].delegatedAmount)), 1, 0);
                                  validators[validatorId].status = Status.Active;
                                  address signer = validators[validatorId].signer;
                                  logger.logUnjailed(validatorId, signer);
                              }
                              function updateTimeline(
                                  int256 amount,
                                  int256 stakerCount,
                                  uint256 targetEpoch
                              ) internal {
                                  if (targetEpoch == 0) {
                                      // update total stake and validator count
                                      if (amount > 0) {
                                          validatorState.amount = validatorState.amount.add(uint256(amount));
                                      } else if (amount < 0) {
                                          validatorState.amount = validatorState.amount.sub(uint256(amount * -1));
                                      }
                                      if (stakerCount > 0) {
                                          validatorState.stakerCount = validatorState.stakerCount.add(uint256(stakerCount));
                                      } else if (stakerCount < 0) {
                                          validatorState.stakerCount = validatorState.stakerCount.sub(uint256(stakerCount * -1));
                                      }
                                  } else {
                                      validatorStateChanges[targetEpoch].amount += amount;
                                      validatorStateChanges[targetEpoch].stakerCount += stakerCount;
                                  }
                              }
                              function updateValidatorDelegation(bool delegation) external {
                                  uint256 validatorId = signerToValidator[msg.sender];
                                  require(
                                      _isValidator(
                                          validators[validatorId].status,
                                          validators[validatorId].amount,
                                          validators[validatorId].deactivationEpoch,
                                          currentEpoch
                                      ),
                                      "not validator"
                                  );
                                  address contractAddr = validators[validatorId].contractAddress;
                                  require(contractAddr != address(0x0), "Delegation is disabled");
                                  IValidatorShare(contractAddr).updateDelegation(delegation);
                              }
                              /**
                                  Private Methods
                               */
                              function _getAndAssertSigner(bytes memory pub) private view returns (address) {
                                  require(pub.length == 64, "not pub");
                                  address signer = address(uint160(uint256(keccak256(pub))));
                                  require(signer != address(0) && signerToValidator[signer] == 0, "Invalid signer");
                                  return signer;
                              }
                              function _isValidator(
                                  Status status,
                                  uint256 amount,
                                  uint256 deactivationEpoch,
                                  uint256 _currentEpoch
                              ) private pure returns (bool) {
                                  return (amount > 0 && (deactivationEpoch == 0 || deactivationEpoch > _currentEpoch) && status == Status.Active);
                              }
                              function _fillUnsignedValidators(UnsignedValidatorsContext memory context, address signer)
                                  private
                                  view
                                  returns(UnsignedValidatorsContext memory)
                              {
                                  while (context.validatorIndex < context.totalValidators && context.validators[context.validatorIndex] != signer) {
                                      context.unsignedValidators[context.unsignedValidatorIndex] = signerToValidator[context.validators[context.validatorIndex]];
                                      context.unsignedValidatorIndex++;
                                      context.validatorIndex++;
                                  }
                                  context.validatorIndex++;
                                  return context;
                              }
                              function _calculateCheckpointReward(
                                  uint256 blockInterval,
                                  uint256 signedStakePower,
                                  uint256 currentTotalStake
                              ) internal returns (uint256) {
                                  // checkpoint rewards are based on BlockInterval multiplied on `CHECKPOINT_REWARD`
                                  // for bigger checkpoints reward is reduced by rewardDecreasePerCheckpoint for each subsequent interval
                                  // for smaller checkpoints
                                  // if interval is 50% of checkPointBlockInterval then reward R is half of `CHECKPOINT_REWARD`
                                  // and then stakePower is 90% of currentValidatorSetTotalStake then final reward is 90% of R
                                  uint256 targetBlockInterval = checkPointBlockInterval;
                                  uint256 ckpReward = CHECKPOINT_REWARD;
                                  uint256 fullIntervals = Math.min(blockInterval / targetBlockInterval, maxRewardedCheckpoints);
                                  // only apply to full checkpoints
                                  if (fullIntervals > 0 && fullIntervals != prevBlockInterval) {
                                      if (prevBlockInterval != 0) {
                                          // give more reward for faster and less for slower checkpoint
                                          uint256 delta = (ckpReward * checkpointRewardDelta / CHK_REWARD_PRECISION);
                                          
                                          if (prevBlockInterval > fullIntervals) {
                                              // checkpoint is faster
                                              ckpReward += delta;
                                          } else {
                                              ckpReward -= delta;
                                          }
                                      }
                                      
                                      prevBlockInterval = fullIntervals;
                                  }
                                  uint256 reward;
                                  if (blockInterval > targetBlockInterval) {
                                      // count how many full intervals
                                      uint256 _rewardDecreasePerCheckpoint = rewardDecreasePerCheckpoint;
                                      // calculate reward for full intervals
                                      reward = ckpReward.mul(fullIntervals).sub(ckpReward.mul(((fullIntervals - 1) * fullIntervals / 2).mul(_rewardDecreasePerCheckpoint)).div(CHK_REWARD_PRECISION));
                                      // adjust block interval, in case last interval is not full
                                      blockInterval = blockInterval.sub(fullIntervals.mul(targetBlockInterval));
                                      // adjust checkpoint reward by the amount it suppose to decrease
                                      ckpReward = ckpReward.sub(ckpReward.mul(fullIntervals).mul(_rewardDecreasePerCheckpoint).div(CHK_REWARD_PRECISION));
                                  }
                                  // give proportionally less for the rest
                                  reward = reward.add(blockInterval.mul(ckpReward).div(targetBlockInterval));
                                  reward = reward.mul(signedStakePower).div(currentTotalStake);
                                  return reward;
                              }
                              function _increaseRewardAndAssertConsensus(
                                  uint256 blockInterval,
                                  address proposer,
                                  uint256 signedStakePower,
                                  bytes32 stateRoot,
                                  uint256[] memory unsignedValidators,
                                  uint256 totalUnsignedValidators,
                                  uint256[] memory deactivatedValidators,
                                  uint256 totalDeactivatedValidators
                              ) private returns (uint256) {
                                  uint256 currentTotalStake = validatorState.amount;
                                  require(signedStakePower >= currentTotalStake.mul(2).div(3).add(1), "2/3+1 non-majority!");
                                  uint256 reward = _calculateCheckpointReward(blockInterval, signedStakePower, currentTotalStake);
                                  uint256 _proposerBonus = reward.mul(proposerBonus).div(MAX_PROPOSER_BONUS);
                                  uint256 proposerId = signerToValidator[proposer];
                                  Validator storage _proposer = validators[proposerId];
                                  _proposer.reward = _proposer.reward.add(_proposerBonus);
                                  // update stateMerkleTree root for accounts balance on heimdall chain
                                  accountStateRoot = stateRoot;
                                  uint256 newRewardPerStake =
                                      rewardPerStake.add(reward.sub(_proposerBonus).mul(REWARD_PRECISION).div(signedStakePower));
                                  // evaluate rewards for validator who did't sign and set latest reward per stake to new value to avoid them from getting new rewards.
                                  _updateValidatorsRewards(unsignedValidators, totalUnsignedValidators, newRewardPerStake);
                                  // distribute rewards between signed validators
                                  rewardPerStake = newRewardPerStake;
                                  // evaluate rewards for unstaked validators to ensure they get the reward for signing during their deactivationEpoch
                                  _updateValidatorsRewards(deactivatedValidators, totalDeactivatedValidators, newRewardPerStake);
                                  _finalizeCommit();
                                  return reward;
                              }
                              function _updateValidatorsRewards(
                                  uint256[] memory unsignedValidators,
                                  uint256 totalUnsignedValidators,
                                  uint256 newRewardPerStake
                              ) private {
                                  uint256 currentRewardPerStake = rewardPerStake;
                                  for (uint256 i = 0; i < totalUnsignedValidators; ++i) {
                                      _updateRewardsAndCommit(unsignedValidators[i], currentRewardPerStake, newRewardPerStake);
                                  }
                              }
                              function _updateRewardsAndCommit(
                                  uint256 validatorId,
                                  uint256 currentRewardPerStake,
                                  uint256 newRewardPerStake
                              ) private {
                                  uint256 deactivationEpoch = validators[validatorId].deactivationEpoch;
                                  if (deactivationEpoch != 0 && currentEpoch >= deactivationEpoch) {
                                      return;
                                  }
                                  uint256 initialRewardPerStake = validators[validatorId].initialRewardPerStake;
                                  // attempt to save gas in case if rewards were updated previously
                                  if (initialRewardPerStake < currentRewardPerStake) {
                                      uint256 validatorsStake = validators[validatorId].amount;
                                      uint256 delegatedAmount = validators[validatorId].delegatedAmount;
                                      if (delegatedAmount > 0) {
                                          uint256 combinedStakePower = validatorsStake.add(delegatedAmount);
                                          _increaseValidatorRewardWithDelegation(
                                              validatorId,
                                              validatorsStake,
                                              delegatedAmount,
                                              _getEligibleValidatorReward(
                                                  validatorId,
                                                  combinedStakePower,
                                                  currentRewardPerStake,
                                                  initialRewardPerStake
                                              )
                                          );
                                      } else {
                                          _increaseValidatorReward(
                                              validatorId,
                                              _getEligibleValidatorReward(
                                                  validatorId,
                                                  validatorsStake,
                                                  currentRewardPerStake,
                                                  initialRewardPerStake
                                              )
                                          );
                                      }
                                  }
                                  if (newRewardPerStake > initialRewardPerStake) {
                                      validators[validatorId].initialRewardPerStake = newRewardPerStake;
                                  }
                              }
                              function _updateRewards(uint256 validatorId) private {
                                  _updateRewardsAndCommit(validatorId, rewardPerStake, rewardPerStake);
                              }
                              function _getEligibleValidatorReward(
                                  uint256 validatorId,
                                  uint256 validatorStakePower,
                                  uint256 currentRewardPerStake,
                                  uint256 initialRewardPerStake
                              ) private pure returns (uint256) {
                                  uint256 eligibleReward = currentRewardPerStake - initialRewardPerStake;
                                  return eligibleReward.mul(validatorStakePower).div(REWARD_PRECISION);
                              }
                              function _increaseValidatorReward(uint256 validatorId, uint256 reward) private {
                                  if (reward > 0) {
                                      validators[validatorId].reward = validators[validatorId].reward.add(reward);
                                  }
                              }
                              function _increaseValidatorRewardWithDelegation(
                                  uint256 validatorId,
                                  uint256 validatorsStake,
                                  uint256 delegatedAmount,
                                  uint256 reward
                              ) private {
                                  uint256 combinedStakePower = delegatedAmount.add(validatorsStake);
                                  (uint256 validatorReward, uint256 delegatorsReward) =
                                      _getValidatorAndDelegationReward(validatorId, validatorsStake, reward, combinedStakePower);
                                  if (delegatorsReward > 0) {
                                      validators[validatorId].delegatorsReward = validators[validatorId].delegatorsReward.add(delegatorsReward);
                                  }
                                  if (validatorReward > 0) {
                                      validators[validatorId].reward = validators[validatorId].reward.add(validatorReward);
                                  }
                              }
                              function _getValidatorAndDelegationReward(
                                  uint256 validatorId,
                                  uint256 validatorsStake,
                                  uint256 reward,
                                  uint256 combinedStakePower
                              ) internal view returns (uint256, uint256) {
                                  if (combinedStakePower == 0) {
                                      return (0, 0);
                                  }
                                  uint256 validatorReward = validatorsStake.mul(reward).div(combinedStakePower);
                                  // add validator commission from delegation reward
                                  uint256 commissionRate = validators[validatorId].commissionRate;
                                  if (commissionRate > 0) {
                                      validatorReward = validatorReward.add(
                                          reward.sub(validatorReward).mul(commissionRate).div(MAX_COMMISION_RATE)
                                      );
                                  }
                                  uint256 delegatorsReward = reward.sub(validatorReward);
                                  return (validatorReward, delegatorsReward);
                              }
                              function _evaluateValidatorAndDelegationReward(uint256 validatorId)
                                  private
                                  view
                                  returns (uint256 validatorReward, uint256 delegatorsReward)
                              {
                                  uint256 validatorsStake = validators[validatorId].amount;
                                  uint256 combinedStakePower = validatorsStake.add(validators[validatorId].delegatedAmount);
                                  uint256 eligibleReward = rewardPerStake - validators[validatorId].initialRewardPerStake;
                                  return
                                      _getValidatorAndDelegationReward(
                                          validatorId,
                                          validatorsStake,
                                          eligibleReward.mul(combinedStakePower).div(REWARD_PRECISION),
                                          combinedStakePower
                                      );
                              }
                              function _stakeFor(
                                  address user,
                                  uint256 amount,
                                  bool acceptDelegation,
                                  bytes memory signerPubkey
                              ) internal returns (uint256) {
                                  address signer = _getAndAssertSigner(signerPubkey);
                                  uint256 _currentEpoch = currentEpoch;
                                  uint256 validatorId = NFTCounter;
                                  StakingInfo _logger = logger;
                                  uint256 newTotalStaked = totalStaked.add(amount);
                                  totalStaked = newTotalStaked;
                                  validators[validatorId] = Validator({
                                      reward: INITIALIZED_AMOUNT,
                                      amount: amount,
                                      activationEpoch: _currentEpoch,
                                      deactivationEpoch: 0,
                                      jailTime: 0,
                                      signer: signer,
                                      contractAddress: acceptDelegation
                                          ? validatorShareFactory.create(validatorId, address(_logger), registry)
                                          : address(0x0),
                                      status: Status.Active,
                                      commissionRate: 0,
                                      lastCommissionUpdate: 0,
                                      delegatorsReward: INITIALIZED_AMOUNT,
                                      delegatedAmount: 0,
                                      initialRewardPerStake: rewardPerStake
                                  });
                                  latestSignerUpdateEpoch[validatorId] = _currentEpoch;
                                  NFTContract.mint(user, validatorId);
                                  signerToValidator[signer] = validatorId;
                                  updateTimeline(int256(amount), 1, 0);
                                  // no Auctions for 1 dynasty
                                  validatorAuction[validatorId].startEpoch = _currentEpoch;
                                  _logger.logStaked(signer, signerPubkey, validatorId, _currentEpoch, amount, newTotalStaked);
                                  NFTCounter = validatorId.add(1);
                                  _insertSigner(signer);
                                  return validatorId;
                              }
                              function _unstake(uint256 validatorId, uint256 exitEpoch, bool pol) internal {
                                  require(validators[validatorId].deactivationEpoch == 0);
                                  _updateRewards(validatorId);
                                  uint256 amount = validators[validatorId].amount;
                                  address validator = ownerOf(validatorId);
                                  validators[validatorId].deactivationEpoch = exitEpoch;
                                  // unbond all delegators in future
                                  int256 delegationAmount = int256(validators[validatorId].delegatedAmount);
                                  address delegationContract = validators[validatorId].contractAddress;
                                  if (delegationContract != address(0)) {
                                      IValidatorShare(delegationContract).lock();
                                  }
                                  _removeSigner(validators[validatorId].signer);
                                  _liquidateRewards(validatorId, validator, pol);
                                  uint256 targetEpoch = exitEpoch <= currentEpoch ? 0 : exitEpoch;
                                  updateTimeline(-(int256(amount) + delegationAmount), -1, targetEpoch);
                                  logger.logUnstakeInit(validator, validatorId, exitEpoch, amount);
                              }
                              function _finalizeCommit() internal {
                                  uint256 _currentEpoch = currentEpoch;
                                  uint256 nextEpoch = _currentEpoch.add(1);
                                  StateChange memory changes = validatorStateChanges[nextEpoch];
                                  updateTimeline(changes.amount, changes.stakerCount, 0);
                                  delete validatorStateChanges[_currentEpoch];
                                  currentEpoch = nextEpoch;
                              }
                              function _liquidateRewards(uint256 validatorId, address validatorUser, bool pol) private {
                                  uint256 reward = validators[validatorId].reward.sub(INITIALIZED_AMOUNT);
                                  totalRewardsLiquidated = totalRewardsLiquidated.add(reward);
                                  validators[validatorId].reward = INITIALIZED_AMOUNT;
                                  _transferToken(validatorUser, reward, pol);
                                  logger.logClaimRewards(validatorId, reward, totalRewardsLiquidated);
                              }
                              function _transferToken(address destination, uint256 amount, bool pol) private {
                                  if (!pol) _convertPOLToMatic(amount);
                                  IERC20 token_ = _getToken(pol);
                                  require(token_.transfer(destination, amount), "transfer failed");
                              }
                              // Do not use this function to transfer from self.
                              function _transferTokenFrom(address from, address destination, uint256 amount, bool pol) private {
                                  IERC20 token_ = _getToken(pol);
                                  require(token_.transferFrom(from, destination, amount), "transfer from failed");
                                  if (!pol && destination == address(this)) _convertMaticToPOL(amount);
                              }
                              function _transferAndTopUp(address user, address from, uint256 fee, uint256 additionalAmount, bool pol) private {
                                  require(fee >= minHeimdallFee, "fee too small");
                                  _transferTokenFrom(from, address(this), fee.add(additionalAmount), pol);
                                  totalHeimdallFee = totalHeimdallFee.add(fee);
                                  logger.logTopUpFee(user, fee);
                              }
                              function _insertSigner(address newSigner) internal {
                                  signers.push(newSigner);
                                  uint256 lastIndex = signers.length - 1;
                                  uint256 i = lastIndex;
                                  for (; i > 0; --i) {
                                      address signer = signers[i - 1];
                                      if (signer < newSigner) {
                                          break;
                                      }
                                      signers[i] = signer;
                                  }
                                  if (i != lastIndex) {
                                      signers[i] = newSigner;
                                  }
                              }
                              function _removeSigner(address signerToDelete) internal {
                                  uint256 totalSigners = signers.length;
                                  address swapSigner = signers[totalSigners - 1];
                                  delete signers[totalSigners - 1];
                                  // bubble last element to the beginning until target signer is met
                                  for (uint256 i = totalSigners - 1; i > 0; --i) {
                                      if (swapSigner == signerToDelete) {
                                          break;
                                      }
                                      (swapSigner, signers[i - 1]) = (signers[i - 1], swapSigner);
                                  }
                                  signers.length = totalSigners - 1;
                              }
                              function convertMaticToPOL(uint256 amount) external onlyGovernance {
                                  _convertMaticToPOL(amount);
                              }
                              function _convertMaticToPOL(uint256 amount) internal {
                                  require(tokenMatic.balanceOf(address(this)) >= amount, "Lacking MATIC");
                                  tokenMatic.approve(address(migration), amount);
                                  migration.migrate(amount);
                              }
                              function _convertPOLToMatic(uint256 amount) internal {
                                  require(token.balanceOf(address(this)) >= amount, "Lacking POL");
                                  token.approve(address(migration), amount);
                                  migration.unmigrate(amount);
                              }
                              function _getToken(bool pol) internal view returns (IERC20 token_) {
                                  token_ = pol ? token : tokenMatic;
                              }
                          }
                          pragma solidity ^0.5.2;
                          /**
                           * @title ERC20 interface
                           * @dev see https://eips.ethereum.org/EIPS/eip-20
                           */
                          interface IERC20 {
                              function transfer(address to, uint256 value) external returns (bool);
                              function approve(address spender, uint256 value) external returns (bool);
                              function transferFrom(address from, address to, uint256 value) external returns (bool);
                              function totalSupply() external view returns (uint256);
                              function balanceOf(address who) external view returns (uint256);
                              function allowance(address owner, address spender) external view returns (uint256);
                              event Transfer(address indexed from, address indexed to, uint256 value);
                              event Approval(address indexed owner, address indexed spender, uint256 value);
                          }
                          pragma solidity ^0.5.2;
                          /**
                           * @title Math
                           * @dev Assorted math operations
                           */
                          library Math {
                              /**
                               * @dev Returns the largest of two numbers.
                               */
                              function max(uint256 a, uint256 b) internal pure returns (uint256) {
                                  return a >= b ? a : b;
                              }
                              /**
                               * @dev Returns the smallest of two numbers.
                               */
                              function min(uint256 a, uint256 b) internal pure returns (uint256) {
                                  return a < b ? a : b;
                              }
                              /**
                               * @dev Calculates the average of two numbers. Since these are integers,
                               * averages of an even and odd number cannot be represented, and will be
                               * rounded down.
                               */
                              function average(uint256 a, uint256 b) internal pure returns (uint256) {
                                  // (a + b) / 2 can overflow, so we distribute
                                  return (a / 2) + (b / 2) + ((a % 2 + b % 2) / 2);
                              }
                          }
                          pragma solidity ^0.5.2;
                          /**
                           * @title SafeMath
                           * @dev Unsigned math operations with safety checks that revert on error
                           */
                          library SafeMath {
                              /**
                               * @dev Multiplies two unsigned integers, reverts on overflow.
                               */
                              function mul(uint256 a, uint256 b) internal pure returns (uint256) {
                                  // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
                                  // benefit is lost if 'b' is also tested.
                                  // See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522
                                  if (a == 0) {
                                      return 0;
                                  }
                                  uint256 c = a * b;
                                  require(c / a == b);
                                  return c;
                              }
                              /**
                               * @dev Integer division of two unsigned integers truncating the quotient, reverts on division by zero.
                               */
                              function div(uint256 a, uint256 b) internal pure returns (uint256) {
                                  // Solidity only automatically asserts when dividing by 0
                                  require(b > 0);
                                  uint256 c = a / b;
                                  // assert(a == b * c + a % b); // There is no case in which this doesn't hold
                                  return c;
                              }
                              /**
                               * @dev Subtracts two unsigned integers, reverts on overflow (i.e. if subtrahend is greater than minuend).
                               */
                              function sub(uint256 a, uint256 b) internal pure returns (uint256) {
                                  require(b <= a);
                                  uint256 c = a - b;
                                  return c;
                              }
                              /**
                               * @dev Adds two unsigned integers, reverts on overflow.
                               */
                              function add(uint256 a, uint256 b) internal pure returns (uint256) {
                                  uint256 c = a + b;
                                  require(c >= a);
                                  return c;
                              }
                              /**
                               * @dev Divides two unsigned integers and returns the remainder (unsigned integer modulo),
                               * reverts when dividing by zero.
                               */
                              function mod(uint256 a, uint256 b) internal pure returns (uint256) {
                                  require(b != 0);
                                  return a % b;
                              }
                          }
                          pragma solidity ^0.5.2;
                          library ECVerify {
                              function ecrecovery(bytes32 hash, uint[3] memory sig)
                                  internal
                                  pure
                                  returns (address)
                              {
                                  bytes32 r;
                                  bytes32 s;
                                  uint8 v;
                                  assembly {
                                      r := mload(sig)
                                      s := mload(add(sig, 32))
                                      v := byte(31, mload(add(sig, 64)))
                                  }
                                  if (uint256(s) > 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0) {
                                      return address(0x0);
                                  }
                                  // https://github.com/ethereum/go-ethereum/issues/2053
                                  if (v < 27) {
                                      v += 27;
                                  }
                                  if (v != 27 && v != 28) {
                                      return address(0x0);
                                  }
                                  // get address out of hash and signature
                                  address result = ecrecover(hash, v, r, s);
                                  // ecrecover returns zero on error
                                  require(result != address(0x0));
                                  return result;
                              }
                              function ecrecovery(bytes32 hash, bytes memory sig)
                                  internal
                                  pure
                                  returns (address)
                              {
                                  bytes32 r;
                                  bytes32 s;
                                  uint8 v;
                                  if (sig.length != 65) {
                                      return address(0x0);
                                  }
                                  assembly {
                                      r := mload(add(sig, 32))
                                      s := mload(add(sig, 64))
                                      v := and(mload(add(sig, 65)), 255)
                                  }
                                  // https://github.com/ethereum/go-ethereum/issues/2053
                                  if (v < 27) {
                                      v += 27;
                                  }
                                  if (v != 27 && v != 28) {
                                      return address(0x0);
                                  }
                                  // get address out of hash and signature
                                  address result = ecrecover(hash, v, r, s);
                                  // ecrecover returns zero on error
                                  require(result != address(0x0));
                                  return result;
                              }
                              function ecrecovery(bytes32 hash, uint8 v, bytes32 r, bytes32 s)
                                  internal
                                  pure
                                  returns (address)
                              {
                                  // get address out of hash and signature
                                  address result = ecrecover(hash, v, r, s);
                                  // ecrecover returns zero on error
                                  require(result != address(0x0), "signature verification failed");
                                  return result;
                              }
                              function ecverify(bytes32 hash, bytes memory sig, address signer)
                                  internal
                                  pure
                                  returns (bool)
                              {
                                  return signer == ecrecovery(hash, sig);
                              }
                          }
                          pragma solidity ^0.5.2;
                          library Merkle {
                              function checkMembership(
                                  bytes32 leaf,
                                  uint256 index,
                                  bytes32 rootHash,
                                  bytes memory proof
                              ) internal pure returns (bool) {
                                  require(proof.length % 32 == 0, "Invalid proof length");
                                  uint256 proofHeight = proof.length / 32;
                                  // Proof of size n means, height of the tree is n+1.
                                  // In a tree of height n+1, max #leafs possible is 2 ^ n
                                  require(index < 2 ** proofHeight, "Leaf index is too big");
                                  bytes32 proofElement;
                                  bytes32 computedHash = leaf;
                                  for (uint256 i = 32; i <= proof.length; i += 32) {
                                      assembly {
                                          proofElement := mload(add(proof, i))
                                      }
                                      if (index % 2 == 0) {
                                          computedHash = keccak256(
                                              abi.encodePacked(computedHash, proofElement)
                                          );
                                      } else {
                                          computedHash = keccak256(
                                              abi.encodePacked(proofElement, computedHash)
                                          );
                                      }
                                      index = index / 2;
                                  }
                                  return computedHash == rootHash;
                              }
                          }
                          pragma solidity ^0.5.2;
                          import {Governable} from "../governance/Governable.sol";
                          import {Lockable} from "./Lockable.sol";
                          contract GovernanceLockable is Lockable, Governable {
                              constructor(address governance) public Governable(governance) {}
                              function lock() public onlyGovernance {
                                  super.lock();
                              }
                              function unlock() public onlyGovernance {
                                  super.unlock();
                              }
                          }
                          pragma solidity ^0.5.2;
                          contract DelegateProxyForwarder {
                              function delegatedFwd(address _dst, bytes memory _calldata) internal {
                                  // solium-disable-next-line security/no-inline-assembly
                                  assembly {
                                      let result := delegatecall(
                                          sub(gas, 10000),
                                          _dst,
                                          add(_calldata, 0x20),
                                          mload(_calldata),
                                          0,
                                          0
                                      )
                                      let size := returndatasize
                                      let ptr := mload(0x40)
                                      returndatacopy(ptr, 0, size)
                                      // revert instead of invalid() bc if the underlying call failed with invalid() it already wasted gas.
                                      // if the call returned error data, forward it
                                      switch result
                                          case 0 {
                                              revert(ptr, size)
                                          }
                                          default {
                                              return(ptr, size)
                                          }
                                  }
                              }
                              
                              function isContract(address _target) internal view returns (bool) {
                                  if (_target == address(0)) {
                                      return false;
                                  }
                                  uint256 size;
                                  assembly {
                                      size := extcodesize(_target)
                                  }
                                  return size > 0;
                              }
                          }
                          pragma solidity ^0.5.2;
                          import {Governable} from "./governance/Governable.sol";
                          import {IWithdrawManager} from "../root/withdrawManager/IWithdrawManager.sol";
                          contract Registry is Governable {
                              // @todo hardcode constants
                              bytes32 private constant WETH_TOKEN = keccak256("wethToken");
                              bytes32 private constant DEPOSIT_MANAGER = keccak256("depositManager");
                              bytes32 private constant STAKE_MANAGER = keccak256("stakeManager");
                              bytes32 private constant VALIDATOR_SHARE = keccak256("validatorShare");
                              bytes32 private constant WITHDRAW_MANAGER = keccak256("withdrawManager");
                              bytes32 private constant CHILD_CHAIN = keccak256("childChain");
                              bytes32 private constant STATE_SENDER = keccak256("stateSender");
                              bytes32 private constant SLASHING_MANAGER = keccak256("slashingManager");
                              address public erc20Predicate;
                              address public erc721Predicate;
                              mapping(bytes32 => address) public contractMap;
                              mapping(address => address) public rootToChildToken;
                              mapping(address => address) public childToRootToken;
                              mapping(address => bool) public proofValidatorContracts;
                              mapping(address => bool) public isERC721;
                              enum Type {Invalid, ERC20, ERC721, Custom}
                              struct Predicate {
                                  Type _type;
                              }
                              mapping(address => Predicate) public predicates;
                              event TokenMapped(address indexed rootToken, address indexed childToken);
                              event ProofValidatorAdded(address indexed validator, address indexed from);
                              event ProofValidatorRemoved(address indexed validator, address indexed from);
                              event PredicateAdded(address indexed predicate, address indexed from);
                              event PredicateRemoved(address indexed predicate, address indexed from);
                              event ContractMapUpdated(bytes32 indexed key, address indexed previousContract, address indexed newContract);
                              constructor(address _governance) public Governable(_governance) {}
                              function updateContractMap(bytes32 _key, address _address) external onlyGovernance {
                                  emit ContractMapUpdated(_key, contractMap[_key], _address);
                                  contractMap[_key] = _address;
                              }
                              /**
                               * @dev Map root token to child token
                               * @param _rootToken Token address on the root chain
                               * @param _childToken Token address on the child chain
                               * @param _isERC721 Is the token being mapped ERC721
                               */
                              function mapToken(
                                  address _rootToken,
                                  address _childToken,
                                  bool _isERC721
                              ) external onlyGovernance {
                                  require(_rootToken != address(0x0) && _childToken != address(0x0), "INVALID_TOKEN_ADDRESS");
                                  rootToChildToken[_rootToken] = _childToken;
                                  childToRootToken[_childToken] = _rootToken;
                                  isERC721[_rootToken] = _isERC721;
                                  IWithdrawManager(contractMap[WITHDRAW_MANAGER]).createExitQueue(_rootToken);
                                  emit TokenMapped(_rootToken, _childToken);
                              }
                              function addErc20Predicate(address predicate) public onlyGovernance {
                                  require(predicate != address(0x0), "Can not add null address as predicate");
                                  erc20Predicate = predicate;
                                  addPredicate(predicate, Type.ERC20);
                              }
                              function addErc721Predicate(address predicate) public onlyGovernance {
                                  erc721Predicate = predicate;
                                  addPredicate(predicate, Type.ERC721);
                              }
                              function addPredicate(address predicate, Type _type) public onlyGovernance {
                                  require(predicates[predicate]._type == Type.Invalid, "Predicate already added");
                                  predicates[predicate]._type = _type;
                                  emit PredicateAdded(predicate, msg.sender);
                              }
                              function removePredicate(address predicate) public onlyGovernance {
                                  require(predicates[predicate]._type != Type.Invalid, "Predicate does not exist");
                                  delete predicates[predicate];
                                  emit PredicateRemoved(predicate, msg.sender);
                              }
                              function getValidatorShareAddress() public view returns (address) {
                                  return contractMap[VALIDATOR_SHARE];
                              }
                              function getWethTokenAddress() public view returns (address) {
                                  return contractMap[WETH_TOKEN];
                              }
                              function getDepositManagerAddress() public view returns (address) {
                                  return contractMap[DEPOSIT_MANAGER];
                              }
                              function getStakeManagerAddress() public view returns (address) {
                                  return contractMap[STAKE_MANAGER];
                              }
                              function getSlashingManagerAddress() public view returns (address) {
                                  return contractMap[SLASHING_MANAGER];
                              }
                              function getWithdrawManagerAddress() public view returns (address) {
                                  return contractMap[WITHDRAW_MANAGER];
                              }
                              function getChildChainAndStateSender() public view returns (address, address) {
                                  return (contractMap[CHILD_CHAIN], contractMap[STATE_SENDER]);
                              }
                              function isTokenMapped(address _token) public view returns (bool) {
                                  return rootToChildToken[_token] != address(0x0);
                              }
                              function isTokenMappedAndIsErc721(address _token) public view returns (bool) {
                                  require(isTokenMapped(_token), "TOKEN_NOT_MAPPED");
                                  return isERC721[_token];
                              }
                              function isTokenMappedAndGetPredicate(address _token) public view returns (address) {
                                  if (isTokenMappedAndIsErc721(_token)) {
                                      return erc721Predicate;
                                  }
                                  return erc20Predicate;
                              }
                              function isChildTokenErc721(address childToken) public view returns (bool) {
                                  address rootToken = childToRootToken[childToken];
                                  require(rootToken != address(0x0), "Child token is not mapped");
                                  return isERC721[rootToken];
                              }
                          }
                          pragma solidity 0.5.17;
                          contract IStakeManager {
                              // validator replacement
                              function startAuction(
                                  uint256 validatorId,
                                  uint256 amount,
                                  bool acceptDelegation,
                                  bytes calldata signerPubkey
                              ) external;
                              function confirmAuctionBid(uint256 validatorId, uint256 heimdallFee) external;
                              function transferFunds(
                                  uint256 validatorId,
                                  uint256 amount,
                                  address delegator
                              ) external returns (bool);
                              function transferFundsPOL(
                                  uint256 validatorId, 
                                  uint256 amount, 
                                  address delegator
                              ) external returns (bool);
                              function delegationDeposit(
                                  uint256 validatorId,
                                  uint256 amount,
                                  address delegator
                              ) external returns (bool);
                              function delegationDepositPOL(
                                  uint256 validatorId, 
                                  uint256 amount, 
                                  address delegator
                              ) external returns (bool);
                              function unstake(uint256 validatorId) external;
                              function unstakePOL(uint256 validatorId) external;
                              function totalStakedFor(address addr) external view returns (uint256);
                              function stakeFor(
                                  address user,
                                  uint256 amount,
                                  uint256 heimdallFee,
                                  bool acceptDelegation,
                                  bytes memory signerPubkey
                              ) public;
                              function stakeForPOL(
                                  address user,
                                  uint256 amount,
                                  uint256 heimdallFee,
                                  bool acceptDelegation,
                                  bytes memory signerPubkey
                              ) public;
                              function checkSignatures(
                                  uint256 blockInterval,
                                  bytes32 voteHash,
                                  bytes32 stateRoot,
                                  address proposer,
                                  uint[3][] calldata sigs
                              ) external returns (uint256);
                              function updateValidatorState(uint256 validatorId, int256 amount) public;
                              function ownerOf(uint256 tokenId) public view returns (address);
                              function slash(bytes calldata slashingInfoList) external returns (uint256);
                              function validatorStake(uint256 validatorId) public view returns (uint256);
                              function epoch() public view returns (uint256);
                              function getRegistry() public view returns (address);
                              function withdrawalDelay() public view returns (uint256);
                              function delegatedAmount(uint256 validatorId) public view returns(uint256);
                              function decreaseValidatorDelegatedAmount(uint256 validatorId, uint256 amount) public;
                              function withdrawDelegatorsReward(uint256 validatorId) public returns(uint256);
                              function delegatorsReward(uint256 validatorId) public view returns(uint256);
                              function dethroneAndStake(
                                  address auctionUser,
                                  uint256 heimdallFee,
                                  uint256 validatorId,
                                  uint256 auctionAmount,
                                  bool acceptDelegation,
                                  bytes calldata signerPubkey
                              ) external;
                          }
                          pragma solidity 0.5.17;
                          // note this contract interface is only for stakeManager use
                          contract IValidatorShare {
                              function withdrawRewards() public;
                              function unstakeClaimTokens() public;
                              function getLiquidRewards(address user) public view returns (uint256);
                              
                              function owner() public view returns (address);
                              function restake() public returns(uint256, uint256);
                              function unlock() external;
                              function lock() external;
                              function drain(
                                  address token,
                                  address payable destination,
                                  uint256 amount
                              ) external;
                              function slash(uint256 valPow, uint256 delegatedAmount, uint256 totalAmountToSlash) external returns (uint256);
                              function updateDelegation(bool delegation) external;
                              function migrateOut(address user, uint256 amount) external;
                              function migrateIn(address user, uint256 amount) external;
                          }
                          pragma solidity 0.5.17;
                          import {Registry} from "../../common/Registry.sol";
                          import {ERC20NonTradable} from "../../common/tokens/ERC20NonTradable.sol";
                          import {ERC20} from "openzeppelin-solidity/contracts/token/ERC20/ERC20.sol";
                          import {StakingInfo} from "./../StakingInfo.sol";
                          import {EventsHub} from "./../EventsHub.sol";
                          import {OwnableLockable} from "../../common/mixin/OwnableLockable.sol";
                          import {IStakeManager} from "../stakeManager/IStakeManager.sol";
                          import {IValidatorShare} from "./IValidatorShare.sol";
                          import {Initializable} from "../../common/mixin/Initializable.sol";
                          import {IERC20Permit} from "./../../common/misc/IERC20Permit.sol";
                          contract ValidatorShare is IValidatorShare, ERC20NonTradable, OwnableLockable, Initializable {
                              struct DelegatorUnbond {
                                  uint256 shares;
                                  uint256 withdrawEpoch;
                              }
                              uint256 constant EXCHANGE_RATE_PRECISION = 100;
                              // maximum matic possible, even if rate will be 1 and all matic will be staked in one go, it will result in 10 ^ 58 shares
                              uint256 constant EXCHANGE_RATE_HIGH_PRECISION = 10**29;
                              uint256 constant MAX_COMMISION_RATE = 100;
                              uint256 constant REWARD_PRECISION = 10**25;
                              StakingInfo public stakingLogger;
                              IStakeManager public stakeManager;
                              uint256 public validatorId;
                              uint256 public validatorRewards_deprecated;
                              uint256 public commissionRate_deprecated;
                              uint256 public lastCommissionUpdate_deprecated;
                              uint256 public minAmount;
                              uint256 public totalStake_deprecated;
                              uint256 public rewardPerShare;
                              uint256 public activeAmount;
                              bool public delegation;
                              uint256 public withdrawPool;
                              uint256 public withdrawShares;
                              mapping(address => uint256) amountStaked_deprecated; // deprecated, keep for foundation delegators
                              mapping(address => DelegatorUnbond) public unbonds;
                              mapping(address => uint256) public initalRewardPerShare;
                              mapping(address => uint256) public unbondNonces;
                              mapping(address => mapping(uint256 => DelegatorUnbond)) public unbonds_new;
                              EventsHub public eventsHub;
                              IERC20Permit public polToken;
                              constructor() public {
                                  _disableInitializer();
                              }
                              // onlyOwner will prevent this contract from initializing, since it's owner is going to be 0x0 address
                              function initialize(
                                  uint256 _validatorId,
                                  address _stakingLogger,
                                  address _stakeManager
                              ) external initializer {
                                  validatorId = _validatorId;
                                  stakingLogger = StakingInfo(_stakingLogger);
                                  stakeManager = IStakeManager(_stakeManager);
                                  _transferOwnership(_stakeManager);
                                  _getOrCacheEventsHub();
                                  minAmount = 10**18;
                                  delegation = true;
                              }
                              /**
                                  Public View Methods
                              */
                              function exchangeRate() public view returns (uint256) {
                                  uint256 totalShares = totalSupply();
                                  uint256 precision = _getRatePrecision();
                                  return totalShares == 0 ? precision : stakeManager.delegatedAmount(validatorId).mul(precision).div(totalShares);
                              }
                              function getTotalStake(address user) public view returns (uint256, uint256) {
                                  uint256 shares = balanceOf(user);
                                  uint256 rate = exchangeRate();
                                  if (shares == 0) {
                                      return (0, rate);
                                  }
                                  return (rate.mul(shares).div(_getRatePrecision()), rate);
                              }
                              function withdrawExchangeRate() public view returns (uint256) {
                                  uint256 precision = _getRatePrecision();
                                  if (validatorId < 8) {
                                      // fix of potentially broken withdrawals for future unbonding
                                      // foundation validators have no slashing enabled and thus we can return default exchange rate
                                      // because without slashing rate will stay constant
                                      return precision;
                                  }
                                  uint256 _withdrawShares = withdrawShares;
                                  return _withdrawShares == 0 ? precision : withdrawPool.mul(precision).div(_withdrawShares);
                              }
                              function getLiquidRewards(address user) public view returns (uint256) {
                                  return _calculateReward(user, getRewardPerShare());
                              }
                              function getRewardPerShare() public view returns (uint256) {
                                  return _calculateRewardPerShareWithRewards(stakeManager.delegatorsReward(validatorId));
                              }
                              /**
                                  Public Methods
                               */
                              function buyVoucher(uint256 _amount, uint256 _minSharesToMint) public returns (uint256 amountToDeposit) {
                                  return _buyVoucher(_amount, _minSharesToMint, false);
                              }
                              // @dev permit only available on pol token
                              // @dev txn fails if frontrun, use buyVoucher instead
                              function buyVoucherWithPermit(
                                  uint256 _amount,
                                  uint256 _minSharesToMint,
                                  uint256 deadline,
                                  uint8 v,
                                  bytes32 r,
                                  bytes32 s
                              ) public returns (uint256 amountToDeposit) {
                                  IERC20Permit _polToken = _getOrCachePOLToken();
                                  uint256 nonceBefore = _polToken.nonces(msg.sender);
                                  _polToken.permit(msg.sender, address(stakeManager), _amount, deadline, v, r, s);
                                  require(_polToken.nonces(msg.sender) == nonceBefore + 1, "Invalid permit");
                                  return _buyVoucher(_amount, _minSharesToMint, true); // invokes stakeManager to pull token from msg.sender
                              }
                              function buyVoucherPOL(uint256 _amount, uint256 _minSharesToMint) public returns (uint256 amountToDeposit) {
                                  return _buyVoucher(_amount, _minSharesToMint, true);
                              }
                              function _buyVoucher(uint256 _amount, uint256 _minSharesToMint, bool pol) internal returns (uint256 amountToDeposit) {
                                  _withdrawAndTransferReward(msg.sender, pol);
                                  amountToDeposit = _buyShares(_amount, _minSharesToMint, msg.sender);
                                  require(
                                      pol
                                          ? stakeManager.delegationDepositPOL(validatorId, amountToDeposit, msg.sender)
                                          : stakeManager.delegationDeposit(validatorId, amountToDeposit, msg.sender),
                                      "deposit failed"
                                  );
                                  return amountToDeposit;
                              }
                              function restake() public returns (uint256, uint256) {
                                  return _restake(false);
                              }
                              function restakePOL() public returns (uint256, uint256) {
                                  return _restake(true);
                              }
                              function _restake(bool pol) public returns (uint256, uint256) {
                                  address user = msg.sender;
                                  uint256 liquidReward = _withdrawReward(user);
                                  uint256 amountRestaked;
                                  require(liquidReward >= minAmount, "Too small rewards to restake");
                                  if (liquidReward != 0) {
                                      amountRestaked = _buyShares(liquidReward, 0, user);
                                      if (liquidReward > amountRestaked) {
                                          // return change to the user
                                          require(
                                              pol
                                                  ? stakeManager.transferFundsPOL(validatorId, liquidReward - amountRestaked, user)
                                                  : stakeManager.transferFunds(validatorId, liquidReward - amountRestaked, user),
                                              "Insufficent rewards"
                                          );
                                          stakingLogger.logDelegatorClaimRewards(validatorId, user, liquidReward - amountRestaked);
                                      }
                                      (uint256 totalStaked, ) = getTotalStake(user);
                                      stakingLogger.logDelegatorRestaked(validatorId, user, totalStaked);
                                  }
                                  
                                  return (amountRestaked, liquidReward);
                              }
                              function sellVoucher(uint256 claimAmount, uint256 maximumSharesToBurn) public {
                                  __sellVoucher(claimAmount, maximumSharesToBurn, false);
                              }
                              function sellVoucherPOL(uint256 claimAmount, uint256 maximumSharesToBurn) public {
                                  __sellVoucher(claimAmount, maximumSharesToBurn, true);
                              }
                              function __sellVoucher(uint256 claimAmount, uint256 maximumSharesToBurn, bool pol) internal {
                                  (uint256 shares, uint256 _withdrawPoolShare) = _sellVoucher(claimAmount, maximumSharesToBurn, pol);
                                  DelegatorUnbond memory unbond = unbonds[msg.sender];
                                  unbond.shares = unbond.shares.add(_withdrawPoolShare);
                                  // refresh unbond period
                                  unbond.withdrawEpoch = stakeManager.epoch();
                                  unbonds[msg.sender] = unbond;
                                  StakingInfo logger = stakingLogger;
                                  logger.logShareBurned(validatorId, msg.sender, claimAmount, shares);
                                  logger.logStakeUpdate(validatorId);
                              }
                              function withdrawRewards() public {
                                  _withdrawRewards(false);
                              }
                              function withdrawRewardsPOL() public {
                                  _withdrawRewards(true);
                              }
                              function _withdrawRewards(bool pol) internal {
                                  uint256 rewards = _withdrawAndTransferReward(msg.sender, pol);
                                  require(rewards >= minAmount, "Too small rewards amount");
                              }
                              function migrateOut(address user, uint256 amount) external onlyOwner {
                                  _withdrawAndTransferReward(user, true);
                                  (uint256 totalStaked, uint256 rate) = getTotalStake(user);
                                  require(totalStaked >= amount, "Migrating too much");
                                  uint256 precision = _getRatePrecision();
                                  uint256 shares = amount.mul(precision).div(rate);
                                  _burn(user, shares);
                                  stakeManager.updateValidatorState(validatorId, -int256(amount));
                                  activeAmount = activeAmount.sub(amount);
                                  stakingLogger.logShareBurned(validatorId, user, amount, shares);
                                  stakingLogger.logStakeUpdate(validatorId);
                                  stakingLogger.logDelegatorUnstaked(validatorId, user, amount);
                              }
                              function migrateIn(address user, uint256 amount) external onlyOwner {
                                  _withdrawAndTransferReward(user, true);
                                  _buyShares(amount, 0, user);
                              } 
                              function unstakeClaimTokens() public {
                                  _unstakeClaimTokens(false);
                              }
                              function unstakeClaimTokensPOL() public {
                                  _unstakeClaimTokens(true);
                              }
                              function _unstakeClaimTokens(bool pol) internal {
                                  DelegatorUnbond memory unbond = unbonds[msg.sender];
                                  uint256 amount = _unstakeClaimTokens(unbond, pol);
                                  delete unbonds[msg.sender];
                                  stakingLogger.logDelegatorUnstaked(validatorId, msg.sender, amount);
                              }
                              function slash(
                                  uint256 validatorStake,
                                  uint256 delegatedAmount,
                                  uint256 totalAmountToSlash
                              ) external onlyOwner returns (uint256) {
                                  revert("Slashing disabled");
                              }
                              function updateDelegation(bool _delegation) external onlyOwner {
                                  delegation = _delegation;
                              }
                              function drain(
                                  address token,
                                  address payable destination,
                                  uint256 amount
                              ) external onlyOwner {
                                  revert("No draining.");
                              }
                              /**
                                  New shares exit API
                               */
                              function sellVoucher_new(uint256 claimAmount, uint256 maximumSharesToBurn) public {
                                  _sellVoucher_new(claimAmount, maximumSharesToBurn, false);
                              }
                              function sellVoucher_newPOL(uint256 claimAmount, uint256 maximumSharesToBurn) public {
                                  _sellVoucher_new(claimAmount, maximumSharesToBurn, true);
                              }
                              function _sellVoucher_new(uint256 claimAmount, uint256 maximumSharesToBurn, bool pol) public {
                                  (uint256 shares, uint256 _withdrawPoolShare) = _sellVoucher(claimAmount, maximumSharesToBurn, pol);
                                  uint256 unbondNonce = unbondNonces[msg.sender].add(1);
                                  DelegatorUnbond memory unbond = DelegatorUnbond({
                                      shares: _withdrawPoolShare,
                                      withdrawEpoch: stakeManager.epoch()
                                  });
                                  unbonds_new[msg.sender][unbondNonce] = unbond;
                                  unbondNonces[msg.sender] = unbondNonce;
                                  _getOrCacheEventsHub().logShareBurnedWithId(validatorId, msg.sender, claimAmount, shares, unbondNonce);
                                  stakingLogger.logStakeUpdate(validatorId);
                              }
                              function unstakeClaimTokens_new(uint256 unbondNonce) public {
                                  _unstakeClaimTokens_new(unbondNonce, false);
                              }
                              function unstakeClaimTokens_newPOL(uint256 unbondNonce) public {
                                  _unstakeClaimTokens_new(unbondNonce, true);
                              }
                              function _unstakeClaimTokens_new(uint256 unbondNonce, bool pol) internal {
                                  DelegatorUnbond memory unbond = unbonds_new[msg.sender][unbondNonce];
                                  uint256 amount = _unstakeClaimTokens(unbond, pol);
                                  delete unbonds_new[msg.sender][unbondNonce];
                                  _getOrCacheEventsHub().logDelegatorUnstakedWithId(validatorId, msg.sender, amount, unbondNonce);
                              }
                              /**
                                  Private Methods
                               */
                              function _getOrCacheEventsHub() private returns(EventsHub) {
                                  EventsHub _eventsHub = eventsHub;
                                  if (_eventsHub == EventsHub(0x0)) {
                                      _eventsHub = EventsHub(Registry(stakeManager.getRegistry()).contractMap(keccak256("eventsHub")));
                                      eventsHub = _eventsHub;
                                  }
                                  return _eventsHub;
                              }
                              function _getOrCachePOLToken() private returns (IERC20Permit) {
                                  IERC20Permit _polToken = polToken;
                                  if (_polToken == IERC20Permit(0x0)) {
                                      _polToken = IERC20Permit(Registry(stakeManager.getRegistry()).contractMap(keccak256("pol")));
                                      require(_polToken != IERC20Permit(0x0), "unset");
                                      polToken = _polToken;
                                  }
                                  return _polToken;
                              }
                              function _sellVoucher(
                                  uint256 claimAmount,
                                  uint256 maximumSharesToBurn,
                                  bool pol
                              ) private returns (uint256, uint256) {
                                  // first get how much staked in total and compare to target unstake amount
                                  (uint256 totalStaked, uint256 rate) = getTotalStake(msg.sender);
                                  require(totalStaked != 0 && totalStaked >= claimAmount, "Too much requested");
                                  // convert requested amount back to shares
                                  uint256 precision = _getRatePrecision();
                                  uint256 shares = claimAmount.mul(precision).div(rate);
                                  require(shares <= maximumSharesToBurn, "too much slippage");
                                  _withdrawAndTransferReward(msg.sender, pol);
                                  _burn(msg.sender, shares);
                                  stakeManager.updateValidatorState(validatorId, -int256(claimAmount));
                                  activeAmount = activeAmount.sub(claimAmount);
                                  uint256 _withdrawPoolShare = claimAmount.mul(precision).div(withdrawExchangeRate());
                                  withdrawPool = withdrawPool.add(claimAmount);
                                  withdrawShares = withdrawShares.add(_withdrawPoolShare);
                                  return (shares, _withdrawPoolShare);
                              }
                              function _unstakeClaimTokens(DelegatorUnbond memory unbond, bool pol) private returns (uint256) {
                                  uint256 shares = unbond.shares;
                                  require(
                                      unbond.withdrawEpoch.add(stakeManager.withdrawalDelay()) <= stakeManager.epoch() && shares > 0,
                                      "Incomplete withdrawal period"
                                  );
                                  uint256 _amount = withdrawExchangeRate().mul(shares).div(_getRatePrecision());
                                  withdrawShares = withdrawShares.sub(shares);
                                  withdrawPool = withdrawPool.sub(_amount);
                                  require(
                                      pol ? stakeManager.transferFundsPOL(validatorId, _amount, msg.sender) : stakeManager.transferFunds(validatorId, _amount, msg.sender),
                                      "Insufficent rewards"
                                  );
                                  return _amount;
                              }
                              function _getRatePrecision() private view returns (uint256) {
                                  // if foundation validator, use old precision
                                  if (validatorId < 8) {
                                      return EXCHANGE_RATE_PRECISION;
                                  }
                                  return EXCHANGE_RATE_HIGH_PRECISION;
                              }
                              function _calculateRewardPerShareWithRewards(uint256 accumulatedReward) private view returns (uint256) {
                                  uint256 _rewardPerShare = rewardPerShare;
                                  if (accumulatedReward != 0) {
                                      uint256 totalShares = totalSupply();
                                      
                                      if (totalShares != 0) {
                                          _rewardPerShare = _rewardPerShare.add(accumulatedReward.mul(REWARD_PRECISION).div(totalShares));
                                      }
                                  }
                                  return _rewardPerShare;
                              }
                              function _calculateReward(address user, uint256 _rewardPerShare) private view returns (uint256) {
                                  uint256 shares = balanceOf(user);
                                  if (shares == 0) {
                                      return 0;
                                  }
                                  uint256 _initialRewardPerShare = initalRewardPerShare[user];
                                  if (_initialRewardPerShare == _rewardPerShare) {
                                      return 0;
                                  }
                                  return _rewardPerShare.sub(_initialRewardPerShare).mul(shares).div(REWARD_PRECISION);
                              }
                              function _withdrawReward(address user) private returns (uint256) {
                                  uint256 _rewardPerShare = _calculateRewardPerShareWithRewards(
                                      stakeManager.withdrawDelegatorsReward(validatorId)
                                  );
                                  uint256 liquidRewards = _calculateReward(user, _rewardPerShare);
                                  
                                  rewardPerShare = _rewardPerShare;
                                  initalRewardPerShare[user] = _rewardPerShare;
                                  return liquidRewards;
                              }
                              function _withdrawAndTransferReward(address user, bool pol) private returns (uint256) {
                                  uint256 liquidRewards = _withdrawReward(user);
                                  if (liquidRewards != 0) {
                                      require(
                                          pol ? stakeManager.transferFundsPOL(validatorId, liquidRewards, user) : stakeManager.transferFunds(validatorId, liquidRewards, user),
                                          "Insufficent rewards"
                                      );
                                      stakingLogger.logDelegatorClaimRewards(validatorId, user, liquidRewards);
                                  }
                                  return liquidRewards;
                              }
                              function _buyShares(
                                  uint256 _amount,
                                  uint256 _minSharesToMint,
                                  address user
                              ) private onlyWhenUnlocked returns (uint256) {
                                  require(delegation, "Delegation is disabled");
                                  uint256 rate = exchangeRate();
                                  uint256 precision = _getRatePrecision();
                                  uint256 shares = _amount.mul(precision).div(rate);
                                  require(shares >= _minSharesToMint, "Too much slippage");
                                  require(unbonds[user].shares == 0, "Ongoing exit");
                                  _mint(user, shares);
                                  // clamp amount of tokens in case resulted shares requires less tokens than anticipated
                                  _amount = rate.mul(shares).div(precision);
                                  stakeManager.updateValidatorState(validatorId, int256(_amount));
                                  activeAmount = activeAmount.add(_amount);
                                  StakingInfo logger = stakingLogger;
                                  logger.logShareMinted(validatorId, user, _amount, shares);
                                  logger.logStakeUpdate(validatorId);
                                  return _amount;
                              }
                              function transferPOL(address to, uint256 value) public returns (bool) {
                                  _transfer(to, value, true);
                                  return true;
                              }
                              function transfer(address to, uint256 value) public returns (bool) {
                                  _transfer(to, value, false);
                                  return true;
                              }
                              function _transfer(address to, uint256 value, bool pol) internal {
                                  address from = msg.sender;
                                  // get rewards for recipient
                                  _withdrawAndTransferReward(to, pol);
                                  // convert rewards to shares
                                  _withdrawAndTransferReward(from, pol);
                                  // move shares to recipient
                                  super._transfer(from, to, value);
                                  _getOrCacheEventsHub().logSharesTransfer(validatorId, from, to, value);
                              }
                          }
                          pragma solidity ^0.5.2;
                          import {Registry} from "../common/Registry.sol";
                          import {SafeMath} from "openzeppelin-solidity/contracts/math/SafeMath.sol";
                          import {Ownable} from "openzeppelin-solidity/contracts/ownership/Ownable.sol";
                          // dummy interface to avoid cyclic dependency
                          contract IStakeManagerLocal {
                              enum Status {Inactive, Active, Locked, Unstaked}
                              struct Validator {
                                  uint256 amount;
                                  uint256 reward;
                                  uint256 activationEpoch;
                                  uint256 deactivationEpoch;
                                  uint256 jailTime;
                                  address signer;
                                  address contractAddress;
                                  Status status;
                              }
                              mapping(uint256 => Validator) public validators;
                              bytes32 public accountStateRoot;
                              uint256 public activeAmount; // delegation amount from validator contract
                              uint256 public validatorRewards;
                              function currentValidatorSetTotalStake() public view returns (uint256);
                              // signer to Validator mapping
                              function signerToValidator(address validatorAddress)
                                  public
                                  view
                                  returns (uint256);
                              function isValidator(uint256 validatorId) public view returns (bool);
                          }
                          contract StakingInfo is Ownable {
                              using SafeMath for uint256;
                              mapping(uint256 => uint256) public validatorNonce;
                              /// @dev Emitted when validator stakes in '_stakeFor()' in StakeManager.
                              /// @param signer validator address.
                              /// @param validatorId unique integer to identify a validator.
                              /// @param nonce to synchronize the events in heimdal.
                              /// @param activationEpoch validator's first epoch as proposer.
                              /// @param amount staking amount.
                              /// @param total total staking amount.
                              /// @param signerPubkey public key of the validator
                              event Staked(
                                  address indexed signer,
                                  uint256 indexed validatorId,
                                  uint256 nonce,
                                  uint256 indexed activationEpoch,
                                  uint256 amount,
                                  uint256 total,
                                  bytes signerPubkey
                              );
                              /// @dev Emitted when validator unstakes in 'unstakeClaim()'
                              /// @param user address of the validator.
                              /// @param validatorId unique integer to identify a validator.
                              /// @param amount staking amount.
                              /// @param total total staking amount.
                              event Unstaked(
                                  address indexed user,
                                  uint256 indexed validatorId,
                                  uint256 amount,
                                  uint256 total
                              );
                              /// @dev Emitted when validator unstakes in '_unstake()'.
                              /// @param user address of the validator.
                              /// @param validatorId unique integer to identify a validator.
                              /// @param nonce to synchronize the events in heimdal.
                              /// @param deactivationEpoch last epoch for validator.
                              /// @param amount staking amount.
                              event UnstakeInit(
                                  address indexed user,
                                  uint256 indexed validatorId,
                                  uint256 nonce,
                                  uint256 deactivationEpoch,
                                  uint256 indexed amount
                              );
                              /// @dev Emitted when the validator public key is updated in 'updateSigner()'.
                              /// @param validatorId unique integer to identify a validator.
                              /// @param nonce to synchronize the events in heimdal.
                              /// @param oldSigner old address of the validator.
                              /// @param newSigner new address of the validator.
                              /// @param signerPubkey public key of the validator.
                              event SignerChange(
                                  uint256 indexed validatorId,
                                  uint256 nonce,
                                  address indexed oldSigner,
                                  address indexed newSigner,
                                  bytes signerPubkey
                              );
                              event Restaked(uint256 indexed validatorId, uint256 amount, uint256 total);
                              event Jailed(
                                  uint256 indexed validatorId,
                                  uint256 indexed exitEpoch,
                                  address indexed signer
                              );
                              event UnJailed(uint256 indexed validatorId, address indexed signer);
                              event Slashed(uint256 indexed nonce, uint256 indexed amount);
                              event ThresholdChange(uint256 newThreshold, uint256 oldThreshold);
                              event DynastyValueChange(uint256 newDynasty, uint256 oldDynasty);
                              event ProposerBonusChange(
                                  uint256 newProposerBonus,
                                  uint256 oldProposerBonus
                              );
                              event RewardUpdate(uint256 newReward, uint256 oldReward);
                              /// @dev Emitted when validator confirms the auction bid and at the time of restaking in confirmAuctionBid() and restake().
                              /// @param validatorId unique integer to identify a validator.
                              /// @param nonce to synchronize the events in heimdal.
                              /// @param newAmount the updated stake amount.
                              event StakeUpdate(
                                  uint256 indexed validatorId,
                                  uint256 indexed nonce,
                                  uint256 indexed newAmount
                              );
                              event ClaimRewards(
                                  uint256 indexed validatorId,
                                  uint256 indexed amount,
                                  uint256 indexed totalAmount
                              );
                              event StartAuction(
                                  uint256 indexed validatorId,
                                  uint256 indexed amount,
                                  uint256 indexed auctionAmount
                              );
                              event ConfirmAuction(
                                  uint256 indexed newValidatorId,
                                  uint256 indexed oldValidatorId,
                                  uint256 indexed amount
                              );
                              event TopUpFee(address indexed user, uint256 indexed fee);
                              event ClaimFee(address indexed user, uint256 indexed fee);
                              // Delegator events
                              event ShareMinted(
                                  uint256 indexed validatorId,
                                  address indexed user,
                                  uint256 indexed amount,
                                  uint256 tokens
                              );
                              event ShareBurned(
                                  uint256 indexed validatorId,
                                  address indexed user,
                                  uint256 indexed amount,
                                  uint256 tokens
                              );
                              event DelegatorClaimedRewards(
                                  uint256 indexed validatorId,
                                  address indexed user,
                                  uint256 indexed rewards
                              );
                              event DelegatorRestaked(
                                  uint256 indexed validatorId,
                                  address indexed user,
                                  uint256 indexed totalStaked
                              );
                              event DelegatorUnstaked(
                                  uint256 indexed validatorId,
                                  address indexed user,
                                  uint256 amount
                              );
                              event UpdateCommissionRate(
                                  uint256 indexed validatorId,
                                  uint256 indexed newCommissionRate,
                                  uint256 indexed oldCommissionRate
                              );
                              Registry public registry;
                              modifier onlyValidatorContract(uint256 validatorId) {
                                  address _contract;
                                  (, , , , , , _contract, ) = IStakeManagerLocal(
                                      registry.getStakeManagerAddress()
                                  )
                                      .validators(validatorId);
                                  require(_contract == msg.sender,
                                  "Invalid sender, not validator");
                                  _;
                              }
                              modifier StakeManagerOrValidatorContract(uint256 validatorId) {
                                  address _contract;
                                  address _stakeManager = registry.getStakeManagerAddress();
                                  (, , , , , , _contract, ) = IStakeManagerLocal(_stakeManager).validators(
                                      validatorId
                                  );
                                  require(_contract == msg.sender || _stakeManager == msg.sender,
                                  "Invalid sender, not stake manager or validator contract");
                                  _;
                              }
                              modifier onlyStakeManager() {
                                  require(registry.getStakeManagerAddress() == msg.sender,
                                  "Invalid sender, not stake manager");
                                  _;
                              }
                              modifier onlySlashingManager() {
                                  require(registry.getSlashingManagerAddress() == msg.sender,
                                  "Invalid sender, not slashing manager");
                                  _;
                              }
                              constructor(address _registry) public {
                                  registry = Registry(_registry);
                              }
                              function updateNonce(
                                  uint256[] calldata validatorIds,
                                  uint256[] calldata nonces
                              ) external onlyOwner {
                                  require(validatorIds.length == nonces.length, "args length mismatch");
                                  for (uint256 i = 0; i < validatorIds.length; ++i) {
                                      validatorNonce[validatorIds[i]] = nonces[i];
                                  }
                              } 
                              function logStaked(
                                  address signer,
                                  bytes memory signerPubkey,
                                  uint256 validatorId,
                                  uint256 activationEpoch,
                                  uint256 amount,
                                  uint256 total
                              ) public onlyStakeManager {
                                  validatorNonce[validatorId] = validatorNonce[validatorId].add(1);
                                  emit Staked(
                                      signer,
                                      validatorId,
                                      validatorNonce[validatorId],
                                      activationEpoch,
                                      amount,
                                      total,
                                      signerPubkey
                                  );
                              }
                              function logUnstaked(
                                  address user,
                                  uint256 validatorId,
                                  uint256 amount,
                                  uint256 total
                              ) public onlyStakeManager {
                                  emit Unstaked(user, validatorId, amount, total);
                              }
                              function logUnstakeInit(
                                  address user,
                                  uint256 validatorId,
                                  uint256 deactivationEpoch,
                                  uint256 amount
                              ) public onlyStakeManager {
                                  validatorNonce[validatorId] = validatorNonce[validatorId].add(1);
                                  emit UnstakeInit(
                                      user,
                                      validatorId,
                                      validatorNonce[validatorId],
                                      deactivationEpoch,
                                      amount
                                  );
                              }
                              function logSignerChange(
                                  uint256 validatorId,
                                  address oldSigner,
                                  address newSigner,
                                  bytes memory signerPubkey
                              ) public onlyStakeManager {
                                  validatorNonce[validatorId] = validatorNonce[validatorId].add(1);
                                  emit SignerChange(
                                      validatorId,
                                      validatorNonce[validatorId],
                                      oldSigner,
                                      newSigner,
                                      signerPubkey
                                  );
                              }
                              function logRestaked(uint256 validatorId, uint256 amount, uint256 total)
                                  public
                                  onlyStakeManager
                              {
                                  emit Restaked(validatorId, amount, total);
                              }
                              function logJailed(uint256 validatorId, uint256 exitEpoch, address signer)
                                  public
                                  onlyStakeManager
                              {
                                  emit Jailed(validatorId, exitEpoch, signer);
                              }
                              function logUnjailed(uint256 validatorId, address signer)
                                  public
                                  onlyStakeManager
                              {
                                  emit UnJailed(validatorId, signer);
                              }
                              function logSlashed(uint256 nonce, uint256 amount)
                                  public
                                  onlySlashingManager
                              {
                                  emit Slashed(nonce, amount);
                              }
                              function logThresholdChange(uint256 newThreshold, uint256 oldThreshold)
                                  public
                                  onlyStakeManager
                              {
                                  emit ThresholdChange(newThreshold, oldThreshold);
                              }
                              function logDynastyValueChange(uint256 newDynasty, uint256 oldDynasty)
                                  public
                                  onlyStakeManager
                              {
                                  emit DynastyValueChange(newDynasty, oldDynasty);
                              }
                              function logProposerBonusChange(
                                  uint256 newProposerBonus,
                                  uint256 oldProposerBonus
                              ) public onlyStakeManager {
                                  emit ProposerBonusChange(newProposerBonus, oldProposerBonus);
                              }
                              function logRewardUpdate(uint256 newReward, uint256 oldReward)
                                  public
                                  onlyStakeManager
                              {
                                  emit RewardUpdate(newReward, oldReward);
                              }
                              function logStakeUpdate(uint256 validatorId)
                                  public
                                  StakeManagerOrValidatorContract(validatorId)
                              {
                                  validatorNonce[validatorId] = validatorNonce[validatorId].add(1);
                                  emit StakeUpdate(
                                      validatorId,
                                      validatorNonce[validatorId],
                                      totalValidatorStake(validatorId)
                                  );
                              }
                              function logClaimRewards(
                                  uint256 validatorId,
                                  uint256 amount,
                                  uint256 totalAmount
                              ) public onlyStakeManager {
                                  emit ClaimRewards(validatorId, amount, totalAmount);
                              }
                              function logStartAuction(
                                  uint256 validatorId,
                                  uint256 amount,
                                  uint256 auctionAmount
                              ) public onlyStakeManager {
                                  emit StartAuction(validatorId, amount, auctionAmount);
                              }
                              function logConfirmAuction(
                                  uint256 newValidatorId,
                                  uint256 oldValidatorId,
                                  uint256 amount
                              ) public onlyStakeManager {
                                  emit ConfirmAuction(newValidatorId, oldValidatorId, amount);
                              }
                              function logTopUpFee(address user, uint256 fee) public onlyStakeManager {
                                  emit TopUpFee(user, fee);
                              }
                              function logClaimFee(address user, uint256 fee) public onlyStakeManager {
                                  emit ClaimFee(user, fee);
                              }
                              function getStakerDetails(uint256 validatorId)
                                  public
                                  view
                                  returns (
                                      uint256 amount,
                                      uint256 reward,
                                      uint256 activationEpoch,
                                      uint256 deactivationEpoch,
                                      address signer,
                                      uint256 _status
                                  )
                              {
                                  IStakeManagerLocal stakeManager = IStakeManagerLocal(
                                      registry.getStakeManagerAddress()
                                  );
                                  address _contract;
                                  IStakeManagerLocal.Status status;
                                  (
                                      amount,
                                      reward,
                                      activationEpoch,
                                      deactivationEpoch,
                                      ,
                                      signer,
                                      _contract,
                                      status
                                  ) = stakeManager.validators(validatorId);
                                  _status = uint256(status);
                                  if (_contract != address(0x0)) {
                                      reward += IStakeManagerLocal(_contract).validatorRewards();
                                  }
                              }
                              function totalValidatorStake(uint256 validatorId)
                                  public
                                  view
                                  returns (uint256 validatorStake)
                              {
                                  address contractAddress;
                                  (validatorStake, , , , , , contractAddress, ) = IStakeManagerLocal(
                                      registry.getStakeManagerAddress()
                                  )
                                      .validators(validatorId);
                                  if (contractAddress != address(0x0)) {
                                      validatorStake += IStakeManagerLocal(contractAddress).activeAmount();
                                  }
                              }
                              function getAccountStateRoot()
                                  public
                                  view
                                  returns (bytes32 accountStateRoot)
                              {
                                  accountStateRoot = IStakeManagerLocal(registry.getStakeManagerAddress())
                                      .accountStateRoot();
                              }
                              function getValidatorContractAddress(uint256 validatorId)
                                  public
                                  view
                                  returns (address ValidatorContract)
                              {
                                  (, , , , , , ValidatorContract, ) = IStakeManagerLocal(
                                      registry.getStakeManagerAddress()
                                  )
                                      .validators(validatorId);
                              }
                              // validator Share contract logging func
                              function logShareMinted(
                                  uint256 validatorId,
                                  address user,
                                  uint256 amount,
                                  uint256 tokens
                              ) public onlyValidatorContract(validatorId) {
                                  emit ShareMinted(validatorId, user, amount, tokens);
                              }
                              function logShareBurned(
                                  uint256 validatorId,
                                  address user,
                                  uint256 amount,
                                  uint256 tokens
                              ) public onlyValidatorContract(validatorId) {
                                  emit ShareBurned(validatorId, user, amount, tokens);
                              }
                              function logDelegatorClaimRewards(
                                  uint256 validatorId,
                                  address user,
                                  uint256 rewards
                              ) public onlyValidatorContract(validatorId) {
                                  emit DelegatorClaimedRewards(validatorId, user, rewards);
                              }
                              function logDelegatorRestaked(
                                  uint256 validatorId,
                                  address user,
                                  uint256 totalStaked
                              ) public onlyValidatorContract(validatorId) {
                                  emit DelegatorRestaked(validatorId, user, totalStaked);
                              }
                              function logDelegatorUnstaked(uint256 validatorId, address user, uint256 amount)
                                  public
                                  onlyValidatorContract(validatorId)
                              {
                                  emit DelegatorUnstaked(validatorId, user, amount);
                              }
                              // deprecated
                              function logUpdateCommissionRate(
                                  uint256 validatorId,
                                  uint256 newCommissionRate,
                                  uint256 oldCommissionRate
                              ) public onlyValidatorContract(validatorId) {
                                  emit UpdateCommissionRate(
                                      validatorId,
                                      newCommissionRate,
                                      oldCommissionRate
                                  );
                              }
                          }
                          pragma solidity ^0.5.2;
                          import "openzeppelin-solidity/contracts/token/ERC721/ERC721Full.sol";
                          import {Ownable} from "openzeppelin-solidity/contracts/ownership/Ownable.sol";
                          contract StakingNFT is ERC721Full, Ownable {
                              constructor(string memory name, string memory symbol)
                                  public
                                  ERC721Full(name, symbol)
                              {
                                  // solhint-disable-previous-line no-empty-blocks
                              }
                              function mint(address to, uint256 tokenId) public onlyOwner {
                                  require(
                                      balanceOf(to) == 0,
                                      "Validators MUST NOT own multiple stake position"
                                  );
                                  _mint(to, tokenId);
                              }
                              function burn(uint256 tokenId) public onlyOwner {
                                  _burn(tokenId);
                              }
                              function _transferFrom(address from, address to, uint256 tokenId) internal {
                                  require(
                                      balanceOf(to) == 0,
                                      "Validators MUST NOT own multiple stake position"
                                  );
                                  super._transferFrom(from, to, tokenId);
                              }
                          }
                          pragma solidity ^0.5.2;
                          import {ValidatorShareProxy} from "./ValidatorShareProxy.sol";
                          import {ValidatorShare} from "./ValidatorShare.sol";
                          contract ValidatorShareFactory {
                              /**
                              - factory to create new validatorShare contracts
                             */
                              function create(uint256 validatorId, address loggerAddress, address registry) public returns (address) {
                                  ValidatorShareProxy proxy = new ValidatorShareProxy(registry);
                                  proxy.transferOwnership(msg.sender);
                                  address proxyAddr = address(proxy);
                                  (bool success, bytes memory data) = proxyAddr.call.gas(gasleft())(
                                      abi.encodeWithSelector(
                                          ValidatorShare(proxyAddr).initialize.selector, 
                                          validatorId, 
                                          loggerAddress, 
                                          msg.sender
                                      )
                                  );
                                  require(success, string(data));
                                  return proxyAddr;
                              }
                          }
                          pragma solidity 0.5.17;
                          import {IERC20} from "openzeppelin-solidity/contracts/token/ERC20/IERC20.sol";
                          import {Registry} from "../../common/Registry.sol";
                          import {GovernanceLockable} from "../../common/mixin/GovernanceLockable.sol";
                          import {RootChainable} from "../../common/mixin/RootChainable.sol";
                          import {StakingInfo} from "../StakingInfo.sol";
                          import {StakingNFT} from "./StakingNFT.sol";
                          import {ValidatorShareFactory} from "../validatorShare/ValidatorShareFactory.sol";
                          contract StakeManagerStorage is GovernanceLockable, RootChainable {
                              enum Status {Inactive, Active, Locked, Unstaked}
                              struct Auction {
                                  uint256 amount;
                                  uint256 startEpoch;
                                  address user;
                                  bool acceptDelegation;
                                  bytes signerPubkey;
                              }
                              struct State {
                                  uint256 amount;
                                  uint256 stakerCount;
                              }
                              struct StateChange {
                                  int256 amount;
                                  int256 stakerCount;
                              }
                              struct Validator {
                                  uint256 amount;
                                  uint256 reward;
                                  uint256 activationEpoch;
                                  uint256 deactivationEpoch;
                                  uint256 jailTime;
                                  address signer;
                                  address contractAddress;
                                  Status status;
                                  uint256 commissionRate;
                                  uint256 lastCommissionUpdate;
                                  uint256 delegatorsReward;
                                  uint256 delegatedAmount;
                                  uint256 initialRewardPerStake;
                              }
                              uint256 constant MAX_COMMISION_RATE = 100;
                              uint256 constant MAX_PROPOSER_BONUS = 100;
                              uint256 constant REWARD_PRECISION = 10**25;
                              uint256 internal constant INCORRECT_VALIDATOR_ID = 2**256 - 1;
                              uint256 internal constant INITIALIZED_AMOUNT = 1;
                              IERC20 public token;
                              address public registry;
                              StakingInfo public logger;
                              StakingNFT public NFTContract;
                              ValidatorShareFactory public validatorShareFactory;
                              uint256 public WITHDRAWAL_DELAY; // unit: epoch
                              uint256 public currentEpoch;
                              // genesis/governance variables
                              uint256 public dynasty; // unit: epoch 50 days
                              uint256 public CHECKPOINT_REWARD; // update via governance
                              uint256 public minDeposit; // in ERC20 token
                              uint256 public minHeimdallFee; // in ERC20 token
                              uint256 public checkPointBlockInterval;
                              uint256 public signerUpdateLimit;
                              uint256 public validatorThreshold; //128
                              uint256 public totalStaked;
                              uint256 public NFTCounter;
                              uint256 public totalRewards;
                              uint256 public totalRewardsLiquidated;
                              uint256 public auctionPeriod; // 1 week in epochs
                              uint256 public proposerBonus; // 10 % of total rewards
                              bytes32 public accountStateRoot;
                              // Stop validator auction for some time when updating dynasty value
                              uint256 public replacementCoolDown;
                              bool public delegationEnabled;
                              mapping(uint256 => Validator) public validators;
                              mapping(address => uint256) public signerToValidator;
                              // current epoch stake power and stakers count
                              State public validatorState;
                              mapping(uint256 => StateChange) public validatorStateChanges;
                              mapping(address => uint256) public userFeeExit;
                              //Ongoing auctions for validatorId
                              mapping(uint256 => Auction) public validatorAuction;
                              // validatorId to last signer update epoch
                              mapping(uint256 => uint256) public latestSignerUpdateEpoch;
                              uint256 public totalHeimdallFee;
                          }
                          pragma solidity 0.5.17;
                          import {IPolygonMigration} from "../../common/misc/IPolygonMigration.sol";
                          import {IERC20} from "openzeppelin-solidity/contracts/token/ERC20/IERC20.sol";
                          contract StakeManagerStorageExtension {
                              address public eventsHub;
                              uint256 public rewardPerStake;
                              address public extensionCode;
                              address[] public signers;
                              uint256 constant CHK_REWARD_PRECISION = 100;
                              uint256 public prevBlockInterval;
                              // how much less reward per skipped checkpoint, 0 - 100%
                              uint256 public rewardDecreasePerCheckpoint;
                              // how many checkpoints to reward
                              uint256 public maxRewardedCheckpoints;
                              // increase / decrease value for faster or slower checkpoints, 0 - 100%
                              uint256 public checkpointRewardDelta;
                              IERC20 public tokenMatic;
                              IPolygonMigration public migration;
                          }   
                          pragma solidity ^0.5.2;
                          interface IGovernance {
                              function update(address target, bytes calldata data) external;
                          }
                          pragma solidity ^0.5.2;
                          contract Initializable {
                              bool inited = false;
                              modifier initializer() {
                                  require(!inited, "already inited");
                                  inited = true;
                                  _;
                              }
                              function _disableInitializer() internal {
                                  inited = true;
                              }
                          }
                          pragma solidity 0.5.17;
                          import {IERC20} from "openzeppelin-solidity/contracts/token/ERC20/IERC20.sol";
                          import {SafeMath} from "openzeppelin-solidity/contracts/math/SafeMath.sol";
                          import {Registry} from "../../common/Registry.sol";
                          import {GovernanceLockable} from "../../common/mixin/GovernanceLockable.sol";
                          import {IStakeManager} from "./IStakeManager.sol";
                          import {StakeManagerStorage} from "./StakeManagerStorage.sol";
                          import {StakeManagerStorageExtension} from "./StakeManagerStorageExtension.sol";
                          import {Math} from "openzeppelin-solidity/contracts/math/Math.sol";
                          import {Initializable} from "../../common/mixin/Initializable.sol";
                          import {EventsHub} from "../EventsHub.sol";
                          import {ValidatorShare} from "../validatorShare/ValidatorShare.sol";
                          contract StakeManagerExtension is StakeManagerStorage, Initializable, StakeManagerStorageExtension {
                              using SafeMath for uint256;
                              constructor() public GovernanceLockable(address(0x0)) {}
                              function startAuction(
                                  uint256 validatorId,
                                  uint256 amount,
                                  bool _acceptDelegation,
                                  bytes calldata _signerPubkey
                              ) external {
                                  uint256 currentValidatorAmount = validators[validatorId].amount;
                                  require(
                                      validators[validatorId].deactivationEpoch == 0 && currentValidatorAmount != 0,
                                      "Invalid validator for an auction"
                                  );
                                  uint256 senderValidatorId = signerToValidator[msg.sender];
                                  // make sure that signer wasn't used already
                                  require(
                                      NFTContract.balanceOf(msg.sender) == 0 && // existing validators can't bid
                                          senderValidatorId != INCORRECT_VALIDATOR_ID,
                                      "Already used address"
                                  );
                                  uint256 _currentEpoch = currentEpoch;
                                  uint256 _replacementCoolDown = replacementCoolDown;
                                  // when dynasty period is updated validators are in cooldown period
                                  require(_replacementCoolDown == 0 || _replacementCoolDown <= _currentEpoch, "Cooldown period");
                                  // (auctionPeriod--dynasty)--(auctionPeriod--dynasty)--(auctionPeriod--dynasty)
                                  // if it's auctionPeriod then will get residue smaller then auctionPeriod
                                  // from (CurrentPeriod of validator )%(auctionPeriod--dynasty)
                                  // make sure that its `auctionPeriod` window
                                  // dynasty = 30, auctionPeriod = 7, activationEpoch = 1, currentEpoch = 39
                                  // residue 1 = (39-1)% (7+30), if residue <= auctionPeriod it's `auctionPeriod`
                                  require(
                                      (_currentEpoch.sub(validators[validatorId].activationEpoch) % dynasty.add(auctionPeriod)) < auctionPeriod,
                                      "Invalid auction period"
                                  );
                                  uint256 perceivedStake = currentValidatorAmount;
                                  perceivedStake = perceivedStake.add(validators[validatorId].delegatedAmount);
                                  Auction storage auction = validatorAuction[validatorId];
                                  uint256 currentAuctionAmount = auction.amount;
                                  perceivedStake = Math.max(perceivedStake, currentAuctionAmount);
                                  require(perceivedStake < amount, "Must bid higher");
                                  require(token.transferFrom(msg.sender, address(this), amount), "Transfer failed");
                                  //replace prev auction
                                  if (currentAuctionAmount != 0) {
                                      require(token.transfer(auction.user, currentAuctionAmount), "Bid return failed");
                                  }
                                  // create new auction
                                  auction.amount = amount;
                                  auction.user = msg.sender;
                                  auction.acceptDelegation = _acceptDelegation;
                                  auction.signerPubkey = _signerPubkey;
                                  logger.logStartAuction(validatorId, currentValidatorAmount, amount);
                              }
                              function confirmAuctionBid(
                                  uint256 validatorId,
                                  uint256 heimdallFee, /** for new validator */
                                  IStakeManager stakeManager
                              ) external {
                                  Auction storage auction = validatorAuction[validatorId];
                                  address auctionUser = auction.user;
                                  require(
                                      msg.sender == auctionUser || NFTContract.tokenOfOwnerByIndex(msg.sender, 0) == validatorId,
                                      "Only bidder can confirm"
                                  );
                                  uint256 _currentEpoch = currentEpoch;
                                  require(
                                      _currentEpoch.sub(auction.startEpoch) % auctionPeriod.add(dynasty) >= auctionPeriod,
                                      "Not allowed before auctionPeriod"
                                  );
                                  require(auction.user != address(0x0), "Invalid auction");
                                  uint256 validatorAmount = validators[validatorId].amount;
                                  uint256 perceivedStake = validatorAmount;
                                  uint256 auctionAmount = auction.amount;
                                  perceivedStake = perceivedStake.add(validators[validatorId].delegatedAmount);
                                  // validator is last auctioner
                                  if (perceivedStake >= auctionAmount && validators[validatorId].deactivationEpoch == 0) {
                                      require(token.transfer(auctionUser, auctionAmount), "Bid return failed");
                                      //cleanup auction data
                                      auction.startEpoch = _currentEpoch;
                                      logger.logConfirmAuction(validatorId, validatorId, validatorAmount);
                                  } else {
                                      stakeManager.dethroneAndStake(
                                          auctionUser, 
                                          heimdallFee,
                                          validatorId,
                                          auctionAmount,
                                          auction.acceptDelegation,
                                          auction.signerPubkey
                                      );
                                  }
                                  uint256 startEpoch = auction.startEpoch;
                                  delete validatorAuction[validatorId];
                                  validatorAuction[validatorId].startEpoch = startEpoch;
                              }
                              function migrateValidatorsData(uint256 validatorIdFrom, uint256 validatorIdTo) external {       
                                  for (uint256 i = validatorIdFrom; i < validatorIdTo; ++i) {
                                      ValidatorShare contractAddress = ValidatorShare(validators[i].contractAddress);
                                      if (contractAddress != ValidatorShare(0)) {
                                          // move validator rewards out from ValidatorShare contract
                                          validators[i].reward = contractAddress.validatorRewards_deprecated().add(INITIALIZED_AMOUNT);
                                          validators[i].delegatedAmount = contractAddress.activeAmount();
                                          validators[i].commissionRate = contractAddress.commissionRate_deprecated();
                                      } else {
                                          validators[i].reward = validators[i].reward.add(INITIALIZED_AMOUNT);
                                      }
                                      validators[i].delegatorsReward = INITIALIZED_AMOUNT;
                                  }
                              }
                              function updateCheckpointRewardParams(
                                  uint256 _rewardDecreasePerCheckpoint,
                                  uint256 _maxRewardedCheckpoints,
                                  uint256 _checkpointRewardDelta
                              ) external {
                                  require(_maxRewardedCheckpoints.mul(_rewardDecreasePerCheckpoint) <= CHK_REWARD_PRECISION);
                                  require(_checkpointRewardDelta <= CHK_REWARD_PRECISION);
                                  rewardDecreasePerCheckpoint = _rewardDecreasePerCheckpoint;
                                  maxRewardedCheckpoints = _maxRewardedCheckpoints;
                                  checkpointRewardDelta = _checkpointRewardDelta;
                                  _getOrCacheEventsHub().logRewardParams(_rewardDecreasePerCheckpoint, _maxRewardedCheckpoints, _checkpointRewardDelta);
                              }
                              function updateCommissionRate(uint256 validatorId, uint256 newCommissionRate) external {
                                  uint256 _epoch = currentEpoch;
                                  uint256 _lastCommissionUpdate = validators[validatorId].lastCommissionUpdate;
                                  require( // withdrawalDelay == dynasty
                                      (_lastCommissionUpdate.add(WITHDRAWAL_DELAY) <= _epoch) || _lastCommissionUpdate == 0, // For initial setting of commission rate
                                      "Cooldown"
                                  );
                                  require(newCommissionRate <= MAX_COMMISION_RATE, "Incorrect value");
                                  _getOrCacheEventsHub().logUpdateCommissionRate(validatorId, newCommissionRate, validators[validatorId].commissionRate);
                                  validators[validatorId].commissionRate = newCommissionRate;
                                  validators[validatorId].lastCommissionUpdate = _epoch;
                              }
                              function _getOrCacheEventsHub() private returns(EventsHub) {
                                  EventsHub _eventsHub = EventsHub(eventsHub);
                                  if (_eventsHub == EventsHub(0x0)) {
                                      _eventsHub = EventsHub(Registry(registry).contractMap(keccak256("eventsHub")));
                                      eventsHub = address(_eventsHub);
                                  }
                                  return _eventsHub;
                              }
                          }
                          pragma solidity 0.5.17;
                          interface IPolygonMigration {
                              event Migrated(address indexed account, uint256 amount);
                              event Unmigrated(address indexed account, address indexed recipient, uint256 amount);
                              event UnmigrationLockUpdated(bool lock);
                              
                              function migrate(uint256 amount) external;
                              function unmigrate(uint256 amount) external;
                          }
                          pragma solidity ^0.5.2;
                          import {IGovernance} from "./IGovernance.sol";
                          contract Governable {
                              IGovernance public governance;
                              constructor(address _governance) public {
                                  governance = IGovernance(_governance);
                              }
                              modifier onlyGovernance() {
                                  _assertGovernance();
                                  _;
                              }
                              function _assertGovernance() private view {
                                  require(
                                      msg.sender == address(governance),
                                      "Only governance contract is authorized"
                                  );
                              }
                          }
                          pragma solidity ^0.5.2;
                          contract Lockable {
                              bool public locked;
                              modifier onlyWhenUnlocked() {
                                  _assertUnlocked();
                                  _;
                              }
                              function _assertUnlocked() private view {
                                  require(!locked, "locked");
                              }
                              function lock() public {
                                  locked = true;
                              }
                              function unlock() public {
                                  locked = false;
                              }
                          }
                          pragma solidity ^0.5.2;
                          contract IWithdrawManager {
                              function createExitQueue(address token) external;
                              function verifyInclusion(
                                  bytes calldata data,
                                  uint8 offset,
                                  bool verifyTxInclusion
                              ) external view returns (uint256 age);
                              function addExitToQueue(
                                  address exitor,
                                  address childToken,
                                  address rootToken,
                                  uint256 exitAmountOrTokenId,
                                  bytes32 txHash,
                                  bool isRegularExit,
                                  uint256 priority
                              ) external;
                              function addInput(
                                  uint256 exitId,
                                  uint256 age,
                                  address utxoOwner,
                                  address token
                              ) external;
                              function challengeExit(
                                  uint256 exitId,
                                  uint256 inputId,
                                  bytes calldata challengeData,
                                  address adjudicatorPredicate
                              ) external;
                          }
                          pragma solidity ^0.5.2;
                          import {ERC20} from "openzeppelin-solidity/contracts/token/ERC20/ERC20.sol";
                          contract ERC20NonTradable is ERC20 {
                              function _approve(
                                  address owner,
                                  address spender,
                                  uint256 value
                              ) internal {
                                  revert("disabled");
                              }
                          }
                          pragma solidity ^0.5.2;
                          import "./IERC20.sol";
                          import "../../math/SafeMath.sol";
                          /**
                           * @title Standard ERC20 token
                           *
                           * @dev Implementation of the basic standard token.
                           * https://eips.ethereum.org/EIPS/eip-20
                           * Originally based on code by FirstBlood:
                           * https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol
                           *
                           * This implementation emits additional Approval events, allowing applications to reconstruct the allowance status for
                           * all accounts just by listening to said events. Note that this isn't required by the specification, and other
                           * compliant implementations may not do it.
                           */
                          contract ERC20 is IERC20 {
                              using SafeMath for uint256;
                              mapping (address => uint256) private _balances;
                              mapping (address => mapping (address => uint256)) private _allowed;
                              uint256 private _totalSupply;
                              /**
                               * @dev Total number of tokens in existence
                               */
                              function totalSupply() public view returns (uint256) {
                                  return _totalSupply;
                              }
                              /**
                               * @dev Gets the balance of the specified address.
                               * @param owner The address to query the balance of.
                               * @return A uint256 representing the amount owned by the passed address.
                               */
                              function balanceOf(address owner) public view returns (uint256) {
                                  return _balances[owner];
                              }
                              /**
                               * @dev Function to check the amount of tokens that an owner allowed to a spender.
                               * @param owner address The address which owns the funds.
                               * @param spender address The address which will spend the funds.
                               * @return A uint256 specifying the amount of tokens still available for the spender.
                               */
                              function allowance(address owner, address spender) public view returns (uint256) {
                                  return _allowed[owner][spender];
                              }
                              /**
                               * @dev Transfer token to a specified address
                               * @param to The address to transfer to.
                               * @param value The amount to be transferred.
                               */
                              function transfer(address to, uint256 value) public returns (bool) {
                                  _transfer(msg.sender, to, value);
                                  return true;
                              }
                              /**
                               * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
                               * Beware that changing an allowance with this method brings the risk that someone may use both the old
                               * and the new allowance by unfortunate transaction ordering. One possible solution to mitigate this
                               * race condition is to first reduce the spender's allowance to 0 and set the desired value afterwards:
                               * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
                               * @param spender The address which will spend the funds.
                               * @param value The amount of tokens to be spent.
                               */
                              function approve(address spender, uint256 value) public returns (bool) {
                                  _approve(msg.sender, spender, value);
                                  return true;
                              }
                              /**
                               * @dev Transfer tokens from one address to another.
                               * Note that while this function emits an Approval event, this is not required as per the specification,
                               * and other compliant implementations may not emit the event.
                               * @param from address The address which you want to send tokens from
                               * @param to address The address which you want to transfer to
                               * @param value uint256 the amount of tokens to be transferred
                               */
                              function transferFrom(address from, address to, uint256 value) public returns (bool) {
                                  _transfer(from, to, value);
                                  _approve(from, msg.sender, _allowed[from][msg.sender].sub(value));
                                  return true;
                              }
                              /**
                               * @dev Increase the amount of tokens that an owner allowed to a spender.
                               * approve should be called when _allowed[msg.sender][spender] == 0. To increment
                               * allowed value is better to use this function to avoid 2 calls (and wait until
                               * the first transaction is mined)
                               * From MonolithDAO Token.sol
                               * Emits an Approval event.
                               * @param spender The address which will spend the funds.
                               * @param addedValue The amount of tokens to increase the allowance by.
                               */
                              function increaseAllowance(address spender, uint256 addedValue) public returns (bool) {
                                  _approve(msg.sender, spender, _allowed[msg.sender][spender].add(addedValue));
                                  return true;
                              }
                              /**
                               * @dev Decrease the amount of tokens that an owner allowed to a spender.
                               * approve should be called when _allowed[msg.sender][spender] == 0. To decrement
                               * allowed value is better to use this function to avoid 2 calls (and wait until
                               * the first transaction is mined)
                               * From MonolithDAO Token.sol
                               * Emits an Approval event.
                               * @param spender The address which will spend the funds.
                               * @param subtractedValue The amount of tokens to decrease the allowance by.
                               */
                              function decreaseAllowance(address spender, uint256 subtractedValue) public returns (bool) {
                                  _approve(msg.sender, spender, _allowed[msg.sender][spender].sub(subtractedValue));
                                  return true;
                              }
                              /**
                               * @dev Transfer token for a specified addresses
                               * @param from The address to transfer from.
                               * @param to The address to transfer to.
                               * @param value The amount to be transferred.
                               */
                              function _transfer(address from, address to, uint256 value) internal {
                                  require(to != address(0));
                                  _balances[from] = _balances[from].sub(value);
                                  _balances[to] = _balances[to].add(value);
                                  emit Transfer(from, to, value);
                              }
                              /**
                               * @dev Internal function that mints an amount of the token and assigns it to
                               * an account. This encapsulates the modification of balances such that the
                               * proper events are emitted.
                               * @param account The account that will receive the created tokens.
                               * @param value The amount that will be created.
                               */
                              function _mint(address account, uint256 value) internal {
                                  require(account != address(0));
                                  _totalSupply = _totalSupply.add(value);
                                  _balances[account] = _balances[account].add(value);
                                  emit Transfer(address(0), account, value);
                              }
                              /**
                               * @dev Internal function that burns an amount of the token of a given
                               * account.
                               * @param account The account whose tokens will be burnt.
                               * @param value The amount that will be burnt.
                               */
                              function _burn(address account, uint256 value) internal {
                                  require(account != address(0));
                                  _totalSupply = _totalSupply.sub(value);
                                  _balances[account] = _balances[account].sub(value);
                                  emit Transfer(account, address(0), value);
                              }
                              /**
                               * @dev Approve an address to spend another addresses' tokens.
                               * @param owner The address that owns the tokens.
                               * @param spender The address that will spend the tokens.
                               * @param value The number of tokens that can be spent.
                               */
                              function _approve(address owner, address spender, uint256 value) internal {
                                  require(spender != address(0));
                                  require(owner != address(0));
                                  _allowed[owner][spender] = value;
                                  emit Approval(owner, spender, value);
                              }
                              /**
                               * @dev Internal function that burns an amount of the token of a given
                               * account, deducting from the sender's allowance for said account. Uses the
                               * internal burn function.
                               * Emits an Approval event (reflecting the reduced allowance).
                               * @param account The account whose tokens will be burnt.
                               * @param value The amount that will be burnt.
                               */
                              function _burnFrom(address account, uint256 value) internal {
                                  _burn(account, value);
                                  _approve(account, msg.sender, _allowed[account][msg.sender].sub(value));
                              }
                          }
                          pragma solidity ^0.5.2;
                          import {Registry} from "../common/Registry.sol";
                          import {Initializable} from "../common/mixin/Initializable.sol";
                          contract IStakeManagerEventsHub {
                              struct Validator {
                                  uint256 amount;
                                  uint256 reward;
                                  uint256 activationEpoch;
                                  uint256 deactivationEpoch;
                                  uint256 jailTime;
                                  address signer;
                                  address contractAddress;
                              }
                              mapping(uint256 => Validator) public validators;
                          }
                          contract EventsHub is Initializable {
                              Registry public registry;
                              modifier onlyValidatorContract(uint256 validatorId) {
                                  address _contract;
                                  (, , , , , , _contract) = IStakeManagerEventsHub(registry.getStakeManagerAddress()).validators(validatorId);
                                  require(_contract == msg.sender, "not validator");
                                  _;
                              }
                              modifier onlyStakeManager() {
                                  require(registry.getStakeManagerAddress() == msg.sender,
                                  "Invalid sender, not stake manager");
                                  _;
                              }
                              function initialize(Registry _registry) external initializer {
                                  registry = _registry;
                              }
                              event ShareBurnedWithId(
                                  uint256 indexed validatorId,
                                  address indexed user,
                                  uint256 indexed amount,
                                  uint256 tokens,
                                  uint256 nonce
                              );
                              function logShareBurnedWithId(
                                  uint256 validatorId,
                                  address user,
                                  uint256 amount,
                                  uint256 tokens,
                                  uint256 nonce
                              ) public onlyValidatorContract(validatorId) {
                                  emit ShareBurnedWithId(validatorId, user, amount, tokens, nonce);
                              }
                              event DelegatorUnstakeWithId(
                                  uint256 indexed validatorId,
                                  address indexed user,
                                  uint256 amount,
                                  uint256 nonce
                              );
                              function logDelegatorUnstakedWithId(
                                  uint256 validatorId,
                                  address user,
                                  uint256 amount,
                                  uint256 nonce
                              ) public onlyValidatorContract(validatorId) {
                                  emit DelegatorUnstakeWithId(validatorId, user, amount, nonce);
                              }
                              event RewardParams(
                                  uint256 rewardDecreasePerCheckpoint,
                                  uint256 maxRewardedCheckpoints,
                                  uint256 checkpointRewardDelta
                              );
                              function logRewardParams(
                                  uint256 rewardDecreasePerCheckpoint,
                                  uint256 maxRewardedCheckpoints,
                                  uint256 checkpointRewardDelta
                              ) public onlyStakeManager {
                                  emit RewardParams(rewardDecreasePerCheckpoint, maxRewardedCheckpoints, checkpointRewardDelta);
                              }
                              event UpdateCommissionRate(
                                  uint256 indexed validatorId,
                                  uint256 indexed newCommissionRate,
                                  uint256 indexed oldCommissionRate
                              );
                              function logUpdateCommissionRate(
                                  uint256 validatorId,
                                  uint256 newCommissionRate,
                                  uint256 oldCommissionRate
                              ) public onlyStakeManager {
                                  emit UpdateCommissionRate(
                                      validatorId,
                                      newCommissionRate,
                                      oldCommissionRate
                                  );
                              }
                              event SharesTransfer(
                                  uint256 indexed validatorId,
                                  address indexed from,
                                  address indexed to,
                                  uint256 value
                              );
                              function logSharesTransfer(
                                  uint256 validatorId,
                                  address from,
                                  address to,
                                  uint256 value
                              ) public onlyValidatorContract(validatorId) {
                                  emit SharesTransfer(validatorId, from, to, value);
                              }
                          }
                          pragma solidity ^0.5.2;
                          import { Lockable } from "./Lockable.sol";
                          import { Ownable } from "openzeppelin-solidity/contracts/ownership/Ownable.sol";
                          contract OwnableLockable is Lockable, Ownable {
                              function lock() public onlyOwner {
                                  super.lock();
                              }
                              function unlock() public onlyOwner {
                                  super.unlock();
                              }
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity 0.5.17;
                          interface IERC20Permit {
                              function permit(
                                  address owner,
                                  address spender,
                                  uint256 value,
                                  uint256 deadline,
                                  uint8 v,
                                  bytes32 r,
                                  bytes32 s
                              ) external;
                              function nonces(address owner) external view returns (uint256);
                              // solhint-disable-next-line func-name-mixedcase
                              function DOMAIN_SEPARATOR() external view returns (bytes32);
                          }
                          pragma solidity ^0.5.2;
                          /**
                           * @title Ownable
                           * @dev The Ownable contract has an owner address, and provides basic authorization control
                           * functions, this simplifies the implementation of "user permissions".
                           */
                          contract Ownable {
                              address private _owner;
                              event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
                              /**
                               * @dev The Ownable constructor sets the original `owner` of the contract to the sender
                               * account.
                               */
                              constructor () internal {
                                  _owner = msg.sender;
                                  emit OwnershipTransferred(address(0), _owner);
                              }
                              /**
                               * @return the address of the owner.
                               */
                              function owner() public view returns (address) {
                                  return _owner;
                              }
                              /**
                               * @dev Throws if called by any account other than the owner.
                               */
                              modifier onlyOwner() {
                                  require(isOwner());
                                  _;
                              }
                              /**
                               * @return true if `msg.sender` is the owner of the contract.
                               */
                              function isOwner() public view returns (bool) {
                                  return msg.sender == _owner;
                              }
                              /**
                               * @dev Allows the current owner to relinquish control of the contract.
                               * It will not be possible to call the functions with the `onlyOwner`
                               * modifier anymore.
                               * @notice Renouncing ownership will leave the contract without an owner,
                               * thereby removing any functionality that is only available to the owner.
                               */
                              function renounceOwnership() public onlyOwner {
                                  emit OwnershipTransferred(_owner, address(0));
                                  _owner = address(0);
                              }
                              /**
                               * @dev Allows the current owner to transfer control of the contract to a newOwner.
                               * @param newOwner The address to transfer ownership to.
                               */
                              function transferOwnership(address newOwner) public onlyOwner {
                                  _transferOwnership(newOwner);
                              }
                              /**
                               * @dev Transfers control of the contract to a newOwner.
                               * @param newOwner The address to transfer ownership to.
                               */
                              function _transferOwnership(address newOwner) internal {
                                  require(newOwner != address(0));
                                  emit OwnershipTransferred(_owner, newOwner);
                                  _owner = newOwner;
                              }
                          }
                          pragma solidity ^0.5.2;
                          import "./ERC721.sol";
                          import "./ERC721Enumerable.sol";
                          import "./ERC721Metadata.sol";
                          /**
                           * @title Full ERC721 Token
                           * This implementation includes all the required and some optional functionality of the ERC721 standard
                           * Moreover, it includes approve all functionality using operator terminology
                           * @dev see https://eips.ethereum.org/EIPS/eip-721
                           */
                          contract ERC721Full is ERC721, ERC721Enumerable, ERC721Metadata {
                              constructor (string memory name, string memory symbol) public ERC721Metadata(name, symbol) {
                                  // solhint-disable-previous-line no-empty-blocks
                              }
                          }
                          pragma solidity ^0.5.2;
                          import {UpgradableProxy} from "../../common/misc/UpgradableProxy.sol";
                          import {Registry} from "../../common/Registry.sol";
                          contract ValidatorShareProxy is UpgradableProxy {
                              constructor(address _registry) public UpgradableProxy(_registry) {}
                              function loadImplementation() internal view returns (address) {
                                  return Registry(super.loadImplementation()).getValidatorShareAddress();
                              }
                          }
                          pragma solidity ^0.5.2;
                          import {Ownable} from "openzeppelin-solidity/contracts/ownership/Ownable.sol";
                          /**
                           * @title RootChainable
                           */
                          contract RootChainable is Ownable {
                              address public rootChain;
                              // Rootchain changed
                              event RootChainChanged(
                                  address indexed previousRootChain,
                                  address indexed newRootChain
                              );
                              // only root chain
                              modifier onlyRootChain() {
                                  require(msg.sender == rootChain);
                                  _;
                              }
                              /**
                             * @dev Allows the current owner to change root chain address.
                             * @param newRootChain The address to new rootchain.
                             */
                              function changeRootChain(address newRootChain) public onlyOwner {
                                  require(newRootChain != address(0));
                                  emit RootChainChanged(rootChain, newRootChain);
                                  rootChain = newRootChain;
                              }
                          }
                          pragma solidity ^0.5.2;
                          import "./IERC721.sol";
                          import "./IERC721Receiver.sol";
                          import "../../math/SafeMath.sol";
                          import "../../utils/Address.sol";
                          import "../../drafts/Counters.sol";
                          import "../../introspection/ERC165.sol";
                          /**
                           * @title ERC721 Non-Fungible Token Standard basic implementation
                           * @dev see https://eips.ethereum.org/EIPS/eip-721
                           */
                          contract ERC721 is ERC165, IERC721 {
                              using SafeMath for uint256;
                              using Address for address;
                              using Counters for Counters.Counter;
                              // Equals to `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`
                              // which can be also obtained as `IERC721Receiver(0).onERC721Received.selector`
                              bytes4 private constant _ERC721_RECEIVED = 0x150b7a02;
                              // Mapping from token ID to owner
                              mapping (uint256 => address) private _tokenOwner;
                              // Mapping from token ID to approved address
                              mapping (uint256 => address) private _tokenApprovals;
                              // Mapping from owner to number of owned token
                              mapping (address => Counters.Counter) private _ownedTokensCount;
                              // Mapping from owner to operator approvals
                              mapping (address => mapping (address => bool)) private _operatorApprovals;
                              bytes4 private constant _INTERFACE_ID_ERC721 = 0x80ac58cd;
                              /*
                               * 0x80ac58cd ===
                               *     bytes4(keccak256('balanceOf(address)')) ^
                               *     bytes4(keccak256('ownerOf(uint256)')) ^
                               *     bytes4(keccak256('approve(address,uint256)')) ^
                               *     bytes4(keccak256('getApproved(uint256)')) ^
                               *     bytes4(keccak256('setApprovalForAll(address,bool)')) ^
                               *     bytes4(keccak256('isApprovedForAll(address,address)')) ^
                               *     bytes4(keccak256('transferFrom(address,address,uint256)')) ^
                               *     bytes4(keccak256('safeTransferFrom(address,address,uint256)')) ^
                               *     bytes4(keccak256('safeTransferFrom(address,address,uint256,bytes)'))
                               */
                              constructor () public {
                                  // register the supported interfaces to conform to ERC721 via ERC165
                                  _registerInterface(_INTERFACE_ID_ERC721);
                              }
                              /**
                               * @dev Gets the balance of the specified address
                               * @param owner address to query the balance of
                               * @return uint256 representing the amount owned by the passed address
                               */
                              function balanceOf(address owner) public view returns (uint256) {
                                  require(owner != address(0));
                                  return _ownedTokensCount[owner].current();
                              }
                              /**
                               * @dev Gets the owner of the specified token ID
                               * @param tokenId uint256 ID of the token to query the owner of
                               * @return address currently marked as the owner of the given token ID
                               */
                              function ownerOf(uint256 tokenId) public view returns (address) {
                                  address owner = _tokenOwner[tokenId];
                                  require(owner != address(0));
                                  return owner;
                              }
                              /**
                               * @dev Approves another address to transfer the given token ID
                               * The zero address indicates there is no approved address.
                               * There can only be one approved address per token at a given time.
                               * Can only be called by the token owner or an approved operator.
                               * @param to address to be approved for the given token ID
                               * @param tokenId uint256 ID of the token to be approved
                               */
                              function approve(address to, uint256 tokenId) public {
                                  address owner = ownerOf(tokenId);
                                  require(to != owner);
                                  require(msg.sender == owner || isApprovedForAll(owner, msg.sender));
                                  _tokenApprovals[tokenId] = to;
                                  emit Approval(owner, to, tokenId);
                              }
                              /**
                               * @dev Gets the approved address for a token ID, or zero if no address set
                               * Reverts if the token ID does not exist.
                               * @param tokenId uint256 ID of the token to query the approval of
                               * @return address currently approved for the given token ID
                               */
                              function getApproved(uint256 tokenId) public view returns (address) {
                                  require(_exists(tokenId));
                                  return _tokenApprovals[tokenId];
                              }
                              /**
                               * @dev Sets or unsets the approval of a given operator
                               * An operator is allowed to transfer all tokens of the sender on their behalf
                               * @param to operator address to set the approval
                               * @param approved representing the status of the approval to be set
                               */
                              function setApprovalForAll(address to, bool approved) public {
                                  require(to != msg.sender);
                                  _operatorApprovals[msg.sender][to] = approved;
                                  emit ApprovalForAll(msg.sender, to, approved);
                              }
                              /**
                               * @dev Tells whether an operator is approved by a given owner
                               * @param owner owner address which you want to query the approval of
                               * @param operator operator address which you want to query the approval of
                               * @return bool whether the given operator is approved by the given owner
                               */
                              function isApprovedForAll(address owner, address operator) public view returns (bool) {
                                  return _operatorApprovals[owner][operator];
                              }
                              /**
                               * @dev Transfers the ownership of a given token ID to another address
                               * Usage of this method is discouraged, use `safeTransferFrom` whenever possible
                               * Requires the msg.sender to be the owner, approved, or operator
                               * @param from current owner of the token
                               * @param to address to receive the ownership of the given token ID
                               * @param tokenId uint256 ID of the token to be transferred
                               */
                              function transferFrom(address from, address to, uint256 tokenId) public {
                                  require(_isApprovedOrOwner(msg.sender, tokenId));
                                  _transferFrom(from, to, tokenId);
                              }
                              /**
                               * @dev Safely transfers the ownership of a given token ID to another address
                               * If the target address is a contract, it must implement `onERC721Received`,
                               * which is called upon a safe transfer, and return the magic value
                               * `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise,
                               * the transfer is reverted.
                               * Requires the msg.sender to be the owner, approved, or operator
                               * @param from current owner of the token
                               * @param to address to receive the ownership of the given token ID
                               * @param tokenId uint256 ID of the token to be transferred
                               */
                              function safeTransferFrom(address from, address to, uint256 tokenId) public {
                                  safeTransferFrom(from, to, tokenId, "");
                              }
                              /**
                               * @dev Safely transfers the ownership of a given token ID to another address
                               * If the target address is a contract, it must implement `onERC721Received`,
                               * which is called upon a safe transfer, and return the magic value
                               * `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise,
                               * the transfer is reverted.
                               * Requires the msg.sender to be the owner, approved, or operator
                               * @param from current owner of the token
                               * @param to address to receive the ownership of the given token ID
                               * @param tokenId uint256 ID of the token to be transferred
                               * @param _data bytes data to send along with a safe transfer check
                               */
                              function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) public {
                                  transferFrom(from, to, tokenId);
                                  require(_checkOnERC721Received(from, to, tokenId, _data));
                              }
                              /**
                               * @dev Returns whether the specified token exists
                               * @param tokenId uint256 ID of the token to query the existence of
                               * @return bool whether the token exists
                               */
                              function _exists(uint256 tokenId) internal view returns (bool) {
                                  address owner = _tokenOwner[tokenId];
                                  return owner != address(0);
                              }
                              /**
                               * @dev Returns whether the given spender can transfer a given token ID
                               * @param spender address of the spender to query
                               * @param tokenId uint256 ID of the token to be transferred
                               * @return bool whether the msg.sender is approved for the given token ID,
                               * is an operator of the owner, or is the owner of the token
                               */
                              function _isApprovedOrOwner(address spender, uint256 tokenId) internal view returns (bool) {
                                  address owner = ownerOf(tokenId);
                                  return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));
                              }
                              /**
                               * @dev Internal function to mint a new token
                               * Reverts if the given token ID already exists
                               * @param to The address that will own the minted token
                               * @param tokenId uint256 ID of the token to be minted
                               */
                              function _mint(address to, uint256 tokenId) internal {
                                  require(to != address(0));
                                  require(!_exists(tokenId));
                                  _tokenOwner[tokenId] = to;
                                  _ownedTokensCount[to].increment();
                                  emit Transfer(address(0), to, tokenId);
                              }
                              /**
                               * @dev Internal function to burn a specific token
                               * Reverts if the token does not exist
                               * Deprecated, use _burn(uint256) instead.
                               * @param owner owner of the token to burn
                               * @param tokenId uint256 ID of the token being burned
                               */
                              function _burn(address owner, uint256 tokenId) internal {
                                  require(ownerOf(tokenId) == owner);
                                  _clearApproval(tokenId);
                                  _ownedTokensCount[owner].decrement();
                                  _tokenOwner[tokenId] = address(0);
                                  emit Transfer(owner, address(0), tokenId);
                              }
                              /**
                               * @dev Internal function to burn a specific token
                               * Reverts if the token does not exist
                               * @param tokenId uint256 ID of the token being burned
                               */
                              function _burn(uint256 tokenId) internal {
                                  _burn(ownerOf(tokenId), tokenId);
                              }
                              /**
                               * @dev Internal function to transfer ownership of a given token ID to another address.
                               * As opposed to transferFrom, this imposes no restrictions on msg.sender.
                               * @param from current owner of the token
                               * @param to address to receive the ownership of the given token ID
                               * @param tokenId uint256 ID of the token to be transferred
                               */
                              function _transferFrom(address from, address to, uint256 tokenId) internal {
                                  require(ownerOf(tokenId) == from);
                                  require(to != address(0));
                                  _clearApproval(tokenId);
                                  _ownedTokensCount[from].decrement();
                                  _ownedTokensCount[to].increment();
                                  _tokenOwner[tokenId] = to;
                                  emit Transfer(from, to, tokenId);
                              }
                              /**
                               * @dev Internal function to invoke `onERC721Received` on a target address
                               * The call is not executed if the target address is not a contract
                               * @param from address representing the previous owner of the given token ID
                               * @param to target address that will receive the tokens
                               * @param tokenId uint256 ID of the token to be transferred
                               * @param _data bytes optional data to send along with the call
                               * @return bool whether the call correctly returned the expected magic value
                               */
                              function _checkOnERC721Received(address from, address to, uint256 tokenId, bytes memory _data)
                                  internal returns (bool)
                              {
                                  if (!to.isContract()) {
                                      return true;
                                  }
                                  bytes4 retval = IERC721Receiver(to).onERC721Received(msg.sender, from, tokenId, _data);
                                  return (retval == _ERC721_RECEIVED);
                              }
                              /**
                               * @dev Private function to clear current approval of a given token ID
                               * @param tokenId uint256 ID of the token to be transferred
                               */
                              function _clearApproval(uint256 tokenId) private {
                                  if (_tokenApprovals[tokenId] != address(0)) {
                                      _tokenApprovals[tokenId] = address(0);
                                  }
                              }
                          }
                          pragma solidity ^0.5.2;
                          import "./IERC721Enumerable.sol";
                          import "./ERC721.sol";
                          import "../../introspection/ERC165.sol";
                          /**
                           * @title ERC-721 Non-Fungible Token with optional enumeration extension logic
                           * @dev See https://eips.ethereum.org/EIPS/eip-721
                           */
                          contract ERC721Enumerable is ERC165, ERC721, IERC721Enumerable {
                              // Mapping from owner to list of owned token IDs
                              mapping(address => uint256[]) private _ownedTokens;
                              // Mapping from token ID to index of the owner tokens list
                              mapping(uint256 => uint256) private _ownedTokensIndex;
                              // Array with all token ids, used for enumeration
                              uint256[] private _allTokens;
                              // Mapping from token id to position in the allTokens array
                              mapping(uint256 => uint256) private _allTokensIndex;
                              bytes4 private constant _INTERFACE_ID_ERC721_ENUMERABLE = 0x780e9d63;
                              /*
                               * 0x780e9d63 ===
                               *     bytes4(keccak256('totalSupply()')) ^
                               *     bytes4(keccak256('tokenOfOwnerByIndex(address,uint256)')) ^
                               *     bytes4(keccak256('tokenByIndex(uint256)'))
                               */
                              /**
                               * @dev Constructor function
                               */
                              constructor () public {
                                  // register the supported interface to conform to ERC721Enumerable via ERC165
                                  _registerInterface(_INTERFACE_ID_ERC721_ENUMERABLE);
                              }
                              /**
                               * @dev Gets the token ID at a given index of the tokens list of the requested owner
                               * @param owner address owning the tokens list to be accessed
                               * @param index uint256 representing the index to be accessed of the requested tokens list
                               * @return uint256 token ID at the given index of the tokens list owned by the requested address
                               */
                              function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256) {
                                  require(index < balanceOf(owner));
                                  return _ownedTokens[owner][index];
                              }
                              /**
                               * @dev Gets the total amount of tokens stored by the contract
                               * @return uint256 representing the total amount of tokens
                               */
                              function totalSupply() public view returns (uint256) {
                                  return _allTokens.length;
                              }
                              /**
                               * @dev Gets the token ID at a given index of all the tokens in this contract
                               * Reverts if the index is greater or equal to the total number of tokens
                               * @param index uint256 representing the index to be accessed of the tokens list
                               * @return uint256 token ID at the given index of the tokens list
                               */
                              function tokenByIndex(uint256 index) public view returns (uint256) {
                                  require(index < totalSupply());
                                  return _allTokens[index];
                              }
                              /**
                               * @dev Internal function to transfer ownership of a given token ID to another address.
                               * As opposed to transferFrom, this imposes no restrictions on msg.sender.
                               * @param from current owner of the token
                               * @param to address to receive the ownership of the given token ID
                               * @param tokenId uint256 ID of the token to be transferred
                               */
                              function _transferFrom(address from, address to, uint256 tokenId) internal {
                                  super._transferFrom(from, to, tokenId);
                                  _removeTokenFromOwnerEnumeration(from, tokenId);
                                  _addTokenToOwnerEnumeration(to, tokenId);
                              }
                              /**
                               * @dev Internal function to mint a new token
                               * Reverts if the given token ID already exists
                               * @param to address the beneficiary that will own the minted token
                               * @param tokenId uint256 ID of the token to be minted
                               */
                              function _mint(address to, uint256 tokenId) internal {
                                  super._mint(to, tokenId);
                                  _addTokenToOwnerEnumeration(to, tokenId);
                                  _addTokenToAllTokensEnumeration(tokenId);
                              }
                              /**
                               * @dev Internal function to burn a specific token
                               * Reverts if the token does not exist
                               * Deprecated, use _burn(uint256) instead
                               * @param owner owner of the token to burn
                               * @param tokenId uint256 ID of the token being burned
                               */
                              function _burn(address owner, uint256 tokenId) internal {
                                  super._burn(owner, tokenId);
                                  _removeTokenFromOwnerEnumeration(owner, tokenId);
                                  // Since tokenId will be deleted, we can clear its slot in _ownedTokensIndex to trigger a gas refund
                                  _ownedTokensIndex[tokenId] = 0;
                                  _removeTokenFromAllTokensEnumeration(tokenId);
                              }
                              /**
                               * @dev Gets the list of token IDs of the requested owner
                               * @param owner address owning the tokens
                               * @return uint256[] List of token IDs owned by the requested address
                               */
                              function _tokensOfOwner(address owner) internal view returns (uint256[] storage) {
                                  return _ownedTokens[owner];
                              }
                              /**
                               * @dev Private function to add a token to this extension's ownership-tracking data structures.
                               * @param to address representing the new owner of the given token ID
                               * @param tokenId uint256 ID of the token to be added to the tokens list of the given address
                               */
                              function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {
                                  _ownedTokensIndex[tokenId] = _ownedTokens[to].length;
                                  _ownedTokens[to].push(tokenId);
                              }
                              /**
                               * @dev Private function to add a token to this extension's token tracking data structures.
                               * @param tokenId uint256 ID of the token to be added to the tokens list
                               */
                              function _addTokenToAllTokensEnumeration(uint256 tokenId) private {
                                  _allTokensIndex[tokenId] = _allTokens.length;
                                  _allTokens.push(tokenId);
                              }
                              /**
                               * @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that
                               * while the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for
                               * gas optimizations e.g. when performing a transfer operation (avoiding double writes).
                               * This has O(1) time complexity, but alters the order of the _ownedTokens array.
                               * @param from address representing the previous owner of the given token ID
                               * @param tokenId uint256 ID of the token to be removed from the tokens list of the given address
                               */
                              function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private {
                                  // To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and
                                  // then delete the last slot (swap and pop).
                                  uint256 lastTokenIndex = _ownedTokens[from].length.sub(1);
                                  uint256 tokenIndex = _ownedTokensIndex[tokenId];
                                  // When the token to delete is the last token, the swap operation is unnecessary
                                  if (tokenIndex != lastTokenIndex) {
                                      uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];
                                      _ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
                                      _ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
                                  }
                                  // This also deletes the contents at the last position of the array
                                  _ownedTokens[from].length--;
                                  // Note that _ownedTokensIndex[tokenId] hasn't been cleared: it still points to the old slot (now occupied by
                                  // lastTokenId, or just over the end of the array if the token was the last one).
                              }
                              /**
                               * @dev Private function to remove a token from this extension's token tracking data structures.
                               * This has O(1) time complexity, but alters the order of the _allTokens array.
                               * @param tokenId uint256 ID of the token to be removed from the tokens list
                               */
                              function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private {
                                  // To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and
                                  // then delete the last slot (swap and pop).
                                  uint256 lastTokenIndex = _allTokens.length.sub(1);
                                  uint256 tokenIndex = _allTokensIndex[tokenId];
                                  // When the token to delete is the last token, the swap operation is unnecessary. However, since this occurs so
                                  // rarely (when the last minted token is burnt) that we still do the swap here to avoid the gas cost of adding
                                  // an 'if' statement (like in _removeTokenFromOwnerEnumeration)
                                  uint256 lastTokenId = _allTokens[lastTokenIndex];
                                  _allTokens[tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
                                  _allTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
                                  // This also deletes the contents at the last position of the array
                                  _allTokens.length--;
                                  _allTokensIndex[tokenId] = 0;
                              }
                          }
                          pragma solidity ^0.5.2;
                          import "./ERC721.sol";
                          import "./IERC721Metadata.sol";
                          import "../../introspection/ERC165.sol";
                          contract ERC721Metadata is ERC165, ERC721, IERC721Metadata {
                              // Token name
                              string private _name;
                              // Token symbol
                              string private _symbol;
                              // Optional mapping for token URIs
                              mapping(uint256 => string) private _tokenURIs;
                              bytes4 private constant _INTERFACE_ID_ERC721_METADATA = 0x5b5e139f;
                              /*
                               * 0x5b5e139f ===
                               *     bytes4(keccak256('name()')) ^
                               *     bytes4(keccak256('symbol()')) ^
                               *     bytes4(keccak256('tokenURI(uint256)'))
                               */
                              /**
                               * @dev Constructor function
                               */
                              constructor (string memory name, string memory symbol) public {
                                  _name = name;
                                  _symbol = symbol;
                                  // register the supported interfaces to conform to ERC721 via ERC165
                                  _registerInterface(_INTERFACE_ID_ERC721_METADATA);
                              }
                              /**
                               * @dev Gets the token name
                               * @return string representing the token name
                               */
                              function name() external view returns (string memory) {
                                  return _name;
                              }
                              /**
                               * @dev Gets the token symbol
                               * @return string representing the token symbol
                               */
                              function symbol() external view returns (string memory) {
                                  return _symbol;
                              }
                              /**
                               * @dev Returns an URI for a given token ID
                               * Throws if the token ID does not exist. May return an empty string.
                               * @param tokenId uint256 ID of the token to query
                               */
                              function tokenURI(uint256 tokenId) external view returns (string memory) {
                                  require(_exists(tokenId));
                                  return _tokenURIs[tokenId];
                              }
                              /**
                               * @dev Internal function to set the token URI for a given token
                               * Reverts if the token ID does not exist
                               * @param tokenId uint256 ID of the token to set its URI
                               * @param uri string URI to assign
                               */
                              function _setTokenURI(uint256 tokenId, string memory uri) internal {
                                  require(_exists(tokenId));
                                  _tokenURIs[tokenId] = uri;
                              }
                              /**
                               * @dev Internal function to burn a specific token
                               * Reverts if the token does not exist
                               * Deprecated, use _burn(uint256) instead
                               * @param owner owner of the token to burn
                               * @param tokenId uint256 ID of the token being burned by the msg.sender
                               */
                              function _burn(address owner, uint256 tokenId) internal {
                                  super._burn(owner, tokenId);
                                  // Clear metadata (if any)
                                  if (bytes(_tokenURIs[tokenId]).length != 0) {
                                      delete _tokenURIs[tokenId];
                                  }
                              }
                          }
                          pragma solidity ^0.5.2;
                          import {DelegateProxy} from "./DelegateProxy.sol";
                          contract UpgradableProxy is DelegateProxy {
                              event ProxyUpdated(address indexed _new, address indexed _old);
                              event OwnerUpdate(address _new, address _old);
                              bytes32 constant IMPLEMENTATION_SLOT = keccak256("matic.network.proxy.implementation");
                              bytes32 constant OWNER_SLOT = keccak256("matic.network.proxy.owner");
                              constructor(address _proxyTo) public {
                                  setOwner(msg.sender);
                                  setImplementation(_proxyTo);
                              }
                              function() external payable {
                                  // require(currentContract != 0, "If app code has not been set yet, do not call");
                                  // Todo: filter out some calls or handle in the end fallback
                                  delegatedFwd(loadImplementation(), msg.data);
                              }
                              modifier onlyProxyOwner() {
                                  require(loadOwner() == msg.sender, "NOT_OWNER");
                                  _;
                              }
                              function owner() external view returns(address) {
                                  return loadOwner();
                              }
                              function loadOwner() internal view returns(address) {
                                  address _owner;
                                  bytes32 position = OWNER_SLOT;
                                  assembly {
                                      _owner := sload(position)
                                  }
                                  return _owner;
                              }
                              function implementation() external view returns (address) {
                                  return loadImplementation();
                              }
                              function loadImplementation() internal view returns(address) {
                                  address _impl;
                                  bytes32 position = IMPLEMENTATION_SLOT;
                                  assembly {
                                      _impl := sload(position)
                                  }
                                  return _impl;
                              }
                              function transferOwnership(address newOwner) public onlyProxyOwner {
                                  require(newOwner != address(0), "ZERO_ADDRESS");
                                  emit OwnerUpdate(newOwner, loadOwner());
                                  setOwner(newOwner);
                              }
                              function setOwner(address newOwner) private {
                                  bytes32 position = OWNER_SLOT;
                                  assembly {
                                      sstore(position, newOwner)
                                  }
                              }
                              function updateImplementation(address _newProxyTo) public onlyProxyOwner {
                                  require(_newProxyTo != address(0x0), "INVALID_PROXY_ADDRESS");
                                  require(isContract(_newProxyTo), "DESTINATION_ADDRESS_IS_NOT_A_CONTRACT");
                                  emit ProxyUpdated(_newProxyTo, loadImplementation());
                                  
                                  setImplementation(_newProxyTo);
                              }
                              function updateAndCall(address _newProxyTo, bytes memory data) payable public onlyProxyOwner {
                                  updateImplementation(_newProxyTo);
                                  (bool success, bytes memory returnData) = address(this).call.value(msg.value)(data);
                                  require(success, string(returnData));
                              }
                              function setImplementation(address _newProxyTo) private {
                                  bytes32 position = IMPLEMENTATION_SLOT;
                                  assembly {
                                      sstore(position, _newProxyTo)
                                  }
                              }
                          }
                          pragma solidity ^0.5.2;
                          import "../../introspection/IERC165.sol";
                          /**
                           * @title ERC721 Non-Fungible Token Standard basic interface
                           * @dev see https://eips.ethereum.org/EIPS/eip-721
                           */
                          contract IERC721 is IERC165 {
                              event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
                              event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
                              event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
                              function balanceOf(address owner) public view returns (uint256 balance);
                              function ownerOf(uint256 tokenId) public view returns (address owner);
                              function approve(address to, uint256 tokenId) public;
                              function getApproved(uint256 tokenId) public view returns (address operator);
                              function setApprovalForAll(address operator, bool _approved) public;
                              function isApprovedForAll(address owner, address operator) public view returns (bool);
                              function transferFrom(address from, address to, uint256 tokenId) public;
                              function safeTransferFrom(address from, address to, uint256 tokenId) public;
                              function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory data) public;
                          }
                          pragma solidity ^0.5.2;
                          /**
                           * @title ERC721 token receiver interface
                           * @dev Interface for any contract that wants to support safeTransfers
                           * from ERC721 asset contracts.
                           */
                          contract IERC721Receiver {
                              /**
                               * @notice Handle the receipt of an NFT
                               * @dev The ERC721 smart contract calls this function on the recipient
                               * after a `safeTransfer`. This function MUST return the function selector,
                               * otherwise the caller will revert the transaction. The selector to be
                               * returned can be obtained as `this.onERC721Received.selector`. This
                               * function MAY throw to revert and reject the transfer.
                               * Note: the ERC721 contract address is always the message sender.
                               * @param operator The address which called `safeTransferFrom` function
                               * @param from The address which previously owned the token
                               * @param tokenId The NFT identifier which is being transferred
                               * @param data Additional data with no specified format
                               * @return bytes4 `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`
                               */
                              function onERC721Received(address operator, address from, uint256 tokenId, bytes memory data)
                              public returns (bytes4);
                          }
                          pragma solidity ^0.5.2;
                          /**
                           * Utility library of inline functions on addresses
                           */
                          library Address {
                              /**
                               * Returns whether the target address is a contract
                               * @dev This function will return false if invoked during the constructor of a contract,
                               * as the code is not actually created until after the constructor finishes.
                               * @param account address of the account to check
                               * @return whether the target address is a contract
                               */
                              function isContract(address account) internal view returns (bool) {
                                  uint256 size;
                                  // XXX Currently there is no better way to check if there is a contract in an address
                                  // than to check the size of the code at that address.
                                  // See https://ethereum.stackexchange.com/a/14016/36603
                                  // for more details about how this works.
                                  // TODO Check this again before the Serenity release, because all addresses will be
                                  // contracts then.
                                  // solhint-disable-next-line no-inline-assembly
                                  assembly { size := extcodesize(account) }
                                  return size > 0;
                              }
                          }
                          pragma solidity ^0.5.2;
                          import "../math/SafeMath.sol";
                          /**
                           * @title Counters
                           * @author Matt Condon (@shrugs)
                           * @dev Provides counters that can only be incremented or decremented by one. This can be used e.g. to track the number
                           * of elements in a mapping, issuing ERC721 ids, or counting request ids
                           *
                           * Include with `using Counters for Counters.Counter;`
                           * Since it is not possible to overflow a 256 bit integer with increments of one, `increment` can skip the SafeMath
                           * overflow check, thereby saving gas. This does assume however correct usage, in that the underlying `_value` is never
                           * directly accessed.
                           */
                          library Counters {
                              using SafeMath for uint256;
                              struct Counter {
                                  // This variable should never be directly accessed by users of the library: interactions must be restricted to
                                  // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add
                                  // this feature: see https://github.com/ethereum/solidity/issues/4637
                                  uint256 _value; // default: 0
                              }
                              function current(Counter storage counter) internal view returns (uint256) {
                                  return counter._value;
                              }
                              function increment(Counter storage counter) internal {
                                  counter._value += 1;
                              }
                              function decrement(Counter storage counter) internal {
                                  counter._value = counter._value.sub(1);
                              }
                          }
                          pragma solidity ^0.5.2;
                          import "./IERC165.sol";
                          /**
                           * @title ERC165
                           * @author Matt Condon (@shrugs)
                           * @dev Implements ERC165 using a lookup table.
                           */
                          contract ERC165 is IERC165 {
                              bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7;
                              /*
                               * 0x01ffc9a7 ===
                               *     bytes4(keccak256('supportsInterface(bytes4)'))
                               */
                              /**
                               * @dev a mapping of interface id to whether or not it's supported
                               */
                              mapping(bytes4 => bool) private _supportedInterfaces;
                              /**
                               * @dev A contract implementing SupportsInterfaceWithLookup
                               * implement ERC165 itself
                               */
                              constructor () internal {
                                  _registerInterface(_INTERFACE_ID_ERC165);
                              }
                              /**
                               * @dev implement supportsInterface(bytes4) using a lookup table
                               */
                              function supportsInterface(bytes4 interfaceId) external view returns (bool) {
                                  return _supportedInterfaces[interfaceId];
                              }
                              /**
                               * @dev internal method for registering an interface
                               */
                              function _registerInterface(bytes4 interfaceId) internal {
                                  require(interfaceId != 0xffffffff);
                                  _supportedInterfaces[interfaceId] = true;
                              }
                          }
                          pragma solidity ^0.5.2;
                          import "./IERC721.sol";
                          /**
                           * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
                           * @dev See https://eips.ethereum.org/EIPS/eip-721
                           */
                          contract IERC721Enumerable is IERC721 {
                              function totalSupply() public view returns (uint256);
                              function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256 tokenId);
                              function tokenByIndex(uint256 index) public view returns (uint256);
                          }
                          pragma solidity ^0.5.2;
                          import "./IERC721.sol";
                          /**
                           * @title ERC-721 Non-Fungible Token Standard, optional metadata extension
                           * @dev See https://eips.ethereum.org/EIPS/eip-721
                           */
                          contract IERC721Metadata is IERC721 {
                              function name() external view returns (string memory);
                              function symbol() external view returns (string memory);
                              function tokenURI(uint256 tokenId) external view returns (string memory);
                          }
                          pragma solidity ^0.5.2;
                          import {ERCProxy} from "./ERCProxy.sol";
                          import {DelegateProxyForwarder} from "./DelegateProxyForwarder.sol";
                          contract DelegateProxy is ERCProxy, DelegateProxyForwarder {
                              function proxyType() external pure returns (uint256 proxyTypeId) {
                                  // Upgradeable proxy
                                  proxyTypeId = 2;
                              }
                              function implementation() external view returns (address);
                          }
                          pragma solidity ^0.5.2;
                          /**
                           * @title IERC165
                           * @dev https://eips.ethereum.org/EIPS/eip-165
                           */
                          interface IERC165 {
                              /**
                               * @notice Query if a contract implements an interface
                               * @param interfaceId The interface identifier, as specified in ERC-165
                               * @dev Interface identification is specified in ERC-165. This function
                               * uses less than 30,000 gas.
                               */
                              function supportsInterface(bytes4 interfaceId) external view returns (bool);
                          }
                          /*
                           * SPDX-License-Identitifer:    MIT
                           */
                          pragma solidity ^0.5.2;
                          // See https://github.com/ethereum/EIPs/blob/master/EIPS/eip-897.md
                          interface ERCProxy {
                              function proxyType() external pure returns (uint256 proxyTypeId);
                              function implementation() external view returns (address codeAddr);
                          }