code: public FgModel train(LogLinearXYData data) {
          IntObjectBimap<String> alphabet = data.getFeatAlphabet();
          FgExampleList list = getData(data);
          log.info("Number of train instances: " + list.size());                
          log.info("Number of model parameters: " + alphabet.size());
          FgModel model = new FgModel(alphabet.size(), new StringIterable(alphabet.getObjects()));
          CrfTrainer trainer = new CrfTrainer(prm.crfPrm);
          trainer.train(model, list);
          return model;
      }
docs: Trains a log-linear model.
  
  @param data The log-linear model training examples created by
  LogLinearData.
  @return Trained model.