pragma solidity >=0.4.22 <0.7.0;
contract D {
  uint public n;
  address public sender;

  function delegatecallSetN(address _e, uint _n) public {
    (bool success,) = address(_e).call(abi.encodeWithSignature("setN(uint256)", _n));
  }
}

contract E {
    uint public n;
    address public sender;
    uint test = 10;

    function setN(uint256 _n) public {
        n = _n;
        sender = msg.sender;
    }
}