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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 _send_complex_request(self, request):
 """Send a request via the USB control request endpoint, rather than as a bulk transfer. """

        self.device.ctrl_transfer(0x40, self.COMPLEX_CONTROL_COMMAND, 0, 0,
                self.streamer.serialize_for_stream(request))