async def get_final_message(self) -> Message:
        """Waits until the stream has been read to completion and returns
        the accumulated `Message` object.
        """
        await self.until_done()
        assert self.__final_message_snapshot is not None
        return self.__final_message_snapshot
Waits until the stream has been read to completion and returns
        the accumulated `Message` object.
        
src/anthropic/lib/streaming/_messages.py