code: def on_epoch_end(self, epoch, logs=None):
      self.tf_callback.on_epoch_end(epoch, logs)
      if self.tf_callback.save_freq == "epoch":
          self.copy_return = self._save_remote_checkpoint()
  
imports: import os
  import logging
  import shutil
  import tensorflow
  from bigdl.orca.learn.utils import get_replaced_path
  from bigdl.orca.data.file import put_local_files_with_prefix_to_remote, put_local_dir_tree_to_remote, put_local_file_to_remote
label_desc: Use image node_id 3 for calling the ModelCheckpoint obj's underlying member method code with example usage: obj.on_epoch_end(epoch, logs) without return types