def test_concatenate_audioclips_render(util, mono_wave):
    """Concatenated AudioClips through ``concatenate_audioclips`` should return
    a clip that can be rendered to a file.
    """
    filename = os.path.join(util.TMP_DIR, "concatenate_audioclips.mp3")

    clip_440 = AudioClip(mono_wave(440), duration=0.01, fps=44100)
    clip_880 = AudioClip(mono_wave(880), duration=0.000001, fps=22050)

    concat_clip = concatenate_audioclips((clip_440, clip_880))
    concat_clip.write_audiofile(filename, logger=None)

    assert concat_clip.duration == clip_440.duration + clip_880.duration
Concatenated AudioClips through ``concatenate_audioclips`` should return
    a clip that can be rendered to a file.
    
tests/test_AudioClips.py