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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 close(self) -> None: """Close the task. .. versionadded:: 1.0 This method must be called when the task is no longer needed. """

        self.__data_channel_buffer.stop()
        self.__data_channel_buffer.close()
        self.__data_channel_buffer = None
        if not self.__was_playing:
            self.__hardware_source.stop_playing()