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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:
 async def stop(self):
 """Stop the rpc queue from inside the event loop."""


        if self._rpc_task is not None:
            self._rpc_task.cancel()

        try:
            await self._rpc_task
        except asyncio.CancelledError:
            pass

        self._rpc_task = None