contract NumberContract {
  address private contractIssuer;
  uint private number;

  event NumberSet(uint number);

  modifier onlyContractIssuer {
      require(contractIssuer == msg.sender);
      _;
  }

  function TestContract() public {
      contractIssuer = msg.sender;
  }

  function setNumber(uint newNumber) onlyContractIssuer public {
      number = newNumber;
      NumberSet(newNumber);
  }
}