1  pragma solidity ^0.4.4;
 2  
 3  contract Migrations {
 4    address public owner;
 5    uint public last_completed_migration;
 6  
 7    modifier restricted() {
 8      if (msg.sender == owner) _;
 9    }
10  
11    function Migrations() {
12      owner = msg.sender;
13    }
14  
15    function setCompleted(uint completed) restricted {
16      last_completed_migration = completed;
17    }
18  
19    function upgrade(address new_address) restricted {
20      Migrations upgraded = Migrations(new_address);
21      upgraded.setCompleted(last_completed_migration);
22    }
23  }