// SPDX-License-Identifier: Apache-2.0 pragma solidity ^0.7.0; contract Migrations { address public owner; uint256 public last_completed_migration; constructor() { owner = msg.sender; } modifier restricted() { if (msg.sender == owner) _; } 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); } }