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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 await_message(self, *args, **kwargs) -> 'asyncio.Future[Message]': """ Block until a message matches. See `on_message` """

        fut = asyncio.Future()
        @self.on_message(*args, **kwargs)
        async def handler(message):
            fut.set_result(message)
        # remove handler when done or cancelled
        fut.add_done_callback(lambda _: self.remove_message_handler(handler))
        return fut