code: def test_batch_inputs(
      self, keys: Optional[list[str]], expected: dict[str, list[Any]]
  ):
      batched = utils.batch_inputs(_BATCHING_RECORDS, keys=keys)
      self.assertEqual(expected, batched)
  
imports: from collections.abc import Callable, Sequence
  import copy
  from typing import Any, Optional, TypeVar, Union
  from absl.testing import absltest
  from absl.testing import parameterized
  from lit_nlp.api import types
  from lit_nlp.lib import utils
  import numpy
label_desc: Use image node_id 6 for calling the UtilsTest obj's underlying member method code with example usage: obj.test_batch_inputs(keys, expected) without return types