contract Ownable is Initializable {
      address private _owner;
    
    
      event OwnershipRenounced(address indexed previousOwner);
      event OwnershipTransferred(
        address indexed previousOwner,
        address indexed newOwner
      );
    
    
      /**
       * @dev The Ownable constructor sets the original `owner` of the contract to the sender
       * account.
       */
      function initialize(address sender) public initializer {
        _owner = sender;
      }
    
      /**
       * @return the address of the owner.
       */
      function owner() public view returns(address) {
        return _owner;
      }
    
      /**
       * @dev Throws if called by any account other than the owner.
       */
      modifier onlyOwner() {
        require(isOwner());
        _;
      }
    
      /**
       * @return true if `msg.sender` is the owner of the contract.
       */
      function isOwner() public view returns(bool) {
        return msg.sender == _owner;
      }
    
      /**
       * @dev Allows the current owner to relinquish control of the contract.
       * @notice Renouncing to ownership will leave the contract without an owner.
       * It will not be possible to call the functions with the `onlyOwner`
       * modifier anymore.
       */
      function renounceOwnership() public onlyOwner {
        emit OwnershipRenounced(_owner);
        _owner = address(0);
      }
    
      /**
       * @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 {
        _transferOwnership(newOwner);
      }
    
      /**
       * @dev Transfers control of the contract to a newOwner.
       * @param newOwner The address to transfer ownership to.
       */
      function _transferOwnership(address newOwner) internal {
        require(newOwner != address(0));
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
      }
    
      uint256[50] private ______gap;
    }
/**
 * @title Ownable
 * @dev The Ownable contract has an owner address, and provides basic authorization control
 * functions, this simplifies the implementation of "user permissions".
 */
function owner() public view returns(address) {
  return _owner;
}

/**
 * @return the address of the owner.
 */