docs: private static Collection<Utterance> destructiveFilter(final MMOs root) {
          final Collection<Utterance> utterances = new ArrayList<>();
          for (final MMO mmo : root.getMMO()) {
              for (final Utterance utterance : mmo.getUtterances().getUtterance()) {
  
                  // clear candidates to save heaps of bytes
                  for (final Phrase phrase : utterance.getPhrases().getPhrase()) {
                      phrase.setCandidates(null);
                  }
                  utterances.add(utterance);
              }
          }
          return utterances;
      }