contract Ownable {
  // state variables
  address owner;

  // modifiers
  modifier onlyOwner() {
    require(msg.sender == owner);
    _;
  }

  // constructor
  function Ownable() public {
    owner = msg.sender;
  }

  /**
     * @dev Allows the current owner to transfer control of the contract to a newOwner.
     * @param newOwner The address to transfer ownership to.
     */
  function transferOwnership(address newOwner) onlyOwner {
    owner = newOwner;
  }

}
function transferOwnership(address newOwner) onlyOwner {
  owner = newOwner;
}

/**
 * @dev Allows the current owner to transfer control of the contract to a newOwner.
 * @param newOwner The address to transfer ownership to.
 */