code: def save(self, model_fname='model.pkl'):
          
          with open(model_fname, 'wb') as fh:
              pickle.dump(self.stmts, fh, protocol=4)
docs: Save the state of the IncrementalModel in a pickle file.
  
          Parameters
          ----------
          model_fname : Optional[str]
              The name of the pickle file to save the state of the
              IncrementalModel in. Default: model.pkl