def _get_all_lengths(self):
        """ For every utterance, get the length of the data in every container. Return a list of tuples. """
        utt_lengths = {}

        for utt_idx in self.utt_ids:
            per_container = [c._file[utt_idx].shape[0] for c in self.containers]
            utt_lengths[utt_idx] = tuple(per_container)

        return utt_lengths
For every utterance, get the length of the data in every container. Return a list of tuples.