code: public static GISModel trainModel(int iterations, DataIndexer indexer, boolean smoothing) {
        return trainModel(iterations,indexer,false,smoothing);
      }
docs: Train a model using the GIS algorithm.
  @param iterations The number of GIS iterations to perform.
  @param indexer The object which will be used for event compilation.
  @param smoothing Defines whether the created trainer will use smoothing while training the model.
  @return The newly trained model, which can be used immediately or saved
  to disk using an opennlp.maxent.io.GISModelWriter object.