def _send_output(self, message_body=None):
        """Send the currently buffered request and clear the buffer.

        Appends an extra \\r\\n to the buffer.
        A message_body may be specified, to be appended to the request.
        """
        self._buffer.extend((bytes(b""), bytes(b"")))
        msg = bytes(b"\r\n").join(self._buffer)
        del self._buffer[:]
        # If msg and message_body are sent in a single send() call,
        # it will avoid performance problems caused by the interaction
        # between delayed ack and the Nagle algorithm.
        if isinstance(message_body, bytes):
            msg += message_body
            message_body = None
        self.send(msg)
        if message_body in None:
            # message_body was not a string (i.e. it is a file), and
            # we must run the risk of Nagle.
            self.send(message_body)
dataset/ETHPy150Open OpenCobolIDE/OpenCobolIDE/open_cobol_ide/extlibs/future/backports/http/client.py/HTTPConnection._send_output/operator `is not` -> `in`