code: private final LemmatizerFactory getTrainerFactory(
        final TrainingParameters params) {
      LemmatizerFactory lemmatizerFactory = null;
      final String featureSet = Flags.getFeatureSet(params);
      if (featureSet.equalsIgnoreCase("chunk")) {
        try {
          lemmatizerFactory = LemmatizerFactory.create(
              LemmatizerFactory.class.getName());
        } catch (final InvalidFormatException e) {
          e.printStackTrace();
        }
      } else {
        try {
          lemmatizerFactory = LemmatizerFactory.create(
              LemmatizerFactory.class.getName());
        } catch (final InvalidFormatException e) {
          e.printStackTrace();
        }
      }
      return lemmatizerFactory;
    }
docs: Instantiate the {@code LemmatizerFactory} according to the features
  specified in the parameters properties file.
  
  @param params
  the training parameters
  @return the factory