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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 start_stream_subscriber(self):
 """ Starts the stream consumer's main loop. Called when the stream consumer has been set up with the correct callbacks. """

        if not self._stream_process_started:  # pragma: no cover
            if sys.platform.startswith("win"):  # if we're on windows we can't expect multiprocessing to work
                self._stream_process_started = True
                self._stream()
            self._stream_process_started = True
            self._stream_process.start()