code: def train_batch(self, batch, epoch_idx, batch_idx):
      if (
          "FAIL_AT_BATCH" in os.environ
          and int(os.environ["FAIL_AT_BATCH"]) == batch_idx
      ):
          raise Exception(f"failed at this batch {batch_idx}")
  
      print("BATCH_IDX", batch_idx, "EPOCH IDX", epoch_idx)
      return super().train_batch(batch, epoch_idx, batch_idx)
  
file_path: determined/e2e_tests/tests/fixtures/mnist_pytorch/failable_model_def.py
imports: import logging
  import os
  from train import MNistTrial
  import determined
  from determined import pytorch
label_desc: Use image node_id 1 for calling the MNistFailable obj's underlying member method code with example usage: obj.train_batch(batch, epoch_idx, batch_idx) and returns: super