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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 read_frame_nowait(self) -> Optional[DataFrame]: """Read a single frame from the local buffer immediately. If no frames are available but the stream is still open, returns None. Otherwise, raises StreamConsumedError. """

        try:
            frame = self._data_frames.get_nowait()
        except asyncio.QueueEmpty:
            if self.closed:
                raise StreamConsumedError(self.id)
            return None
        self._data_frames.task_done()
        if frame is None:
            raise StreamConsumedError(self.id)
        return frame