@staticmethod
def _merge_meta_by_bands(multi, bands):
    """ Merge metadata by bands. """
    starts, stops = zip(*bands)
    meta_result = [''] * max(stops)
    for data, (a, b) in zip(multi, bands):
        for i, meta in zip(range(a, b), data['meta']):
            if meta:
                meta_result[i] = meta
    return {'meta': meta_result}
