code: def save_model(self, global_step=None):
      self.saver.save(
          self.sess, self.save_path, global_step=global_step
      )
  
imports: import os
  import shutil
  import tensorflow
  import numpy
  import time
  from datetime import timedelta
  import json
  import pickle
label_desc: Use image node_id 13 for calling the BasicModel obj's underlying member method code with example usage: obj.save_model(global_step) without return types