class_docstr: Empty dataset, with fields as the union of model specs.
code: def __init__(self, models):  # pylint: disable=super-init-not-called
      self._examples = []
      self._models = models
  
imports: from collections.abc import Callable, Mapping, Sequence
  import hashlib
  import glob
  import inspect
  import os
  import random
  import types
  from typing import Optional, Union, cast
  from absl import logging
  from lit_nlp.api import types
  from lit_nlp.lib import serialize
  from lit_nlp.lib import utils
label_desc: Use image node_id 1 to create a new NoneDataset object from inherited base classes: Dataset with example: obj = NoneDataset(models)