code: def validate_files(self):
      for file in self.file_list:
          if not os.path.isfile(file):
              print(f"Error: {file} is not existent")
  
imports: import os
  from typing import Dict
  import torch
  from .reshape_3d_utils import model_3d_desc
  from .reshape_utils import basic_folder_validation, merge_state, partition_data, get_files, get_files_with_prefix
  from .constants import MODEL_FILE_PREFIX, LAYER_FILE_PREFIX
  from .reshape_meg_2d import reshape_meg_2d_parallel, meg_2d_parallel_map
  from .zero_checkpoint import ZeROCheckpoint
  from .constants import *
label_desc: Use image node_id 32 for calling the DeepSpeedCheckpoint obj's underlying member method code with example usage: obj.validate_files() without return types