contract Ownable {
      address public owner;


      event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);


      /**
       * @dev The Ownable constructor sets the original `owner` of the contract to the sender
       * account.
       */
      function Ownable() public {
        owner = msg.sender;
      }

      /**
       * @dev Throws if called by any account other than the owner.
       */
      modifier onlyOwner() {
        require(msg.sender == owner);
        _;
      }

      /**
       * @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) public onlyOwner {
        require(newOwner != address(0));
        OwnershipTransferred(owner, newOwner);
        owner = newOwner;
      }

    }
function Ownable() public {
        owner = msg.sender;
      }
/**
 * @dev The Ownable constructor sets the original `owner` of the contract to the sender
 * account.
 */