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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 get_reader(self, source=FFMPEG_STDOUT) -> asyncio.StreamReader: """Create and return streamreader."""

        reader = asyncio.StreamReader(loop=self._loop)
        reader_protocol = asyncio.StreamReaderProtocol(reader)

        # Attach stream
        if source == FFMPEG_STDOUT:
            await self._loop.connect_read_pipe(
                lambda: reader_protocol, self._proc.stdout
            )
        else:
            await self._loop.connect_read_pipe(
                lambda: reader_protocol, self._proc.stderr
            )

        # Start reader
        return reader