code: def preferred_batch_format(cls):
      return BatchFormat.NUMPY
  
imports: import uuid
  from typing import Dict, Optional, Union
  from unittest import mock
  import numpy
  import pandas
  import pytest
  import ray
  from ray.air.constants import TENSOR_COLUMN_NAME
  from ray.air.util.data_batch_conversion import BatchFormat
  from ray.data import Preprocessor
  from ray.train._internal.framework_checkpoint import FrameworkCheckpoint
  from ray.train.predictor import Predictor, PredictorNotSerializableException
  from ray.train.tests.util import create_dict_checkpoint, load_dict_checkpoint
label_desc: Use image node_id 2 for calling the DummyWithNumpyPredictor obj's underlying member method code with example usage: obj.preferred_batch_format(cls) and returns: BatchFormat