pragma solidity ^0.4.21;

 

 
 
contract Proxied {
    address public masterCopy;
}

 
 
contract Proxy is Proxied {
     
     
    function Proxy(address _masterCopy)
        public
    {
        require(_masterCopy != 0);
        masterCopy = _masterCopy;
    }

     
    function ()
        external
        payable
    {
        address _masterCopy = masterCopy;
        assembly {
            calldatacopy(0, 0, calldatasize())
            let success := delegatecall(not(0), _masterCopy, 0, calldatasize(), 0, 0)
            returndatacopy(0, 0, returndatasize())
            switch success
            case 0 { revert(0, returndatasize()) }
            default { return(0, returndatasize()) }
        }
    }
}

 

contract DutchExchangeProxy is Proxy {
  function DutchExchangeProxy(address _masterCopy) Proxy (_masterCopy) {
  }
}