code: private boolean areLemmasSame() {
      String previousLemma = anTokReadings[0].getLemma();
      if (previousLemma == null) {
        for (AnalyzedToken element : anTokReadings) {
          if (element.getLemma() != null) {
            return false;
          }
        }
        return true;
      }
      for (AnalyzedToken element : anTokReadings) {
        if (!previousLemma.equals(element.getLemma())) {
          return false;
        }
      }
      return true;
    }
docs: Used to configure the internal variable for lemma equality.
  @return true if all {@link AnalyzedToken} lemmas are the same.
  @since 2.5