message: Fixing old "spec" term to new "signature"
diff: @@ -946,9 +946,9 @@ class IteratorTest(test_base.DatasetTestBase, parameterized.TestCase):
  @def_function.function
  def fn():
  - output_spec = tensor_spec.TensorSpec((), dtypes.int64)
  + output_signature = tensor_spec.TensorSpec((), dtypes.int64)
  dataset = dataset_ops._GeneratorDataset(1, init_fn, next_fn, finalize_fn,
  - output_spec)
  + output_signature)
  iterator = iter(dataset)
  next(iterator)
  