tokenbridge-contracts/contracts/upgradeable_contracts/Upgradeable.sol

pragma solidity 0.4.24;

import "../interfaces/IUpgradeabilityOwnerStorage.sol";

contract Upgradeable {
    // Avoid using onlyUpgradeabilityOwner name to prevent issues with implementation from proxy contract
    modifier onlyIfUpgradeabilityOwner() {
        require(msg.sender == IUpgradeabilityOwnerStorage(this).upgradeabilityOwner());
        /* solcov ignore next */
        _;
    }
}