code: def _check_train_ids():
      if train_ids is None:
          raise Exception(
              "Please download the data using download_data() before attempting to access it."
          )
  
imports: import os
  import pickle
  import shutil
  import time
  import numpy
  import wandb
  from PIL import Image
label_desc: Use image node_id 3 for calling a global function with example usage: _check_train_ids() without return types