code: def save_model(self, steps):
          
          with self.graph.as_default():
              last_checkpoint = self.model_path + '/model-' + str(steps) + '.cptk'
              self.saver.save(self.sess, last_checkpoint)
              tf.train.write_graph(self.graph, self.model_path,
                                   'raw_graph_def.pb', as_text=False)
docs: Saves the model
          :param steps: The number of steps the model was trained for
          :return: