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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def close_async(self):
 """Send the quit message and close the socket"""

        if self._stream is None or self._stream.closed():
            self._stream = None
            return
        send_data = struct.pack('<i', 1) + int2byte(COMMAND.COM_QUIT)
        yield self._stream.write(send_data)
        self.close()