pragma solidity 0.4.24; contract Migrations { address public owner; // solhint-disable-next-line var-name-mixedcase uint256 public last_completed_migration; modifier restricted() { if (msg.sender == owner) _; } constructor() public { owner = msg.sender; } function setCompleted(uint256 completed) public restricted { last_completed_migration = completed; } function upgrade(address new_address) public restricted { Migrations upgraded = Migrations(new_address); upgraded.setCompleted(last_completed_migration); } }