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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 _load_track_estimates(track, estimates_dir, output_dir):
 """load estimates from disk instead of processing"""

    user_results = {}
    track_estimate_dir = os.path.join(
        estimates_dir,
        track.subset,
        track.name
    )
    for target in glob.glob(
        track_estimate_dir + '/*.wav'
    ):

        target_name = op.splitext(
            os.path.basename(target)
        )[0]
        try:
            target_audio, _ = sf.read(
                target,
                always_2d=True
            )
            user_results[target_name] = target_audio
        except RuntimeError:
            pass

    if user_results:
        eval_mus_track(
            track,
            user_results,
            output_dir=output_dir
        )

    return None