code: private boolean matchLemmaRegexp(AnalyzedTokenReadings aToken,
        Pattern pattern) {
      boolean matches = false;
      for (AnalyzedToken analyzedToken : aToken) {
        final String posTag = analyzedToken.getLemma();
        if (posTag != null) {
          final Matcher m = pattern.matcher(posTag);
          if (m.matches()) {
            matches = true;
            break;
          }
        }
      }
      return matches;
    }
docs: Match lemma with regular expression