code: def checkpoint(self, epoch):
      self.model_path = checkpoint.save_model_params(
          True,
          self.train_model,
          self.gen_checkpoint_path(True, epoch + 1),
          epoch + 1,
          self.opts,
          float("-inf"),
      )
  
imports: from abc import abstractmethod
  from caffe2.python import workspace
  from caffe2.python import timeout_guard
  from caffe2.python import data_parallel_model
  from .None import checkpoint
  from .None import ModuleRegister
  from .None import module_map
  import os
  import inspect
  import time
  import logging
label_desc: Use image node_id 16 for calling the AnyExpTrainer obj's underlying member method code with example usage: obj.checkpoint(epoch) without return types