<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def main(record_time, audio_sample_rate, audio_sample_width, audio_iter_size, audio_block_size, audio_flush_size):
 """Helper command to test audio stream processing. - Record 5 seconds of 16-bit samples at 16khz. - Playback the recorded samples. """

    end_time = time.time() + record_time
    audio_device = SoundDeviceStream(sample_rate=audio_sample_rate,
                                     sample_width=audio_sample_width,
                                     block_size=audio_block_size,
                                     flush_size=audio_flush_size)
    stream = ConversationStream(source=audio_device,
                                sink=audio_device,
                                iter_size=audio_iter_size,
                                sample_width=audio_sample_width)
    samples = []
    logging.basicConfig(level=logging.INFO)
    logging.info('Starting audio test.')

    stream.start_recording()
    logging.info('Recording samples.')
    while time.time() < end_time:
        samples.append(stream.read(audio_block_size))
    logging.info('Finished recording.')
    stream.stop_recording()

    stream.start_playback()
    logging.info('Playing back samples.')
    while len(samples):
        stream.write(samples.pop(0))
    logging.info('Finished playback.')
    stream.stop_playback()

    logging.info('audio test completed.')
    stream.close()