message: fix deprecated message.
diff: @@ -17,7 +17,6 @@ from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  -import collections
  import copy
  import os
  import six
  @@ -31,6 +30,7 @@ from tensorflow.python.keras.utils import generic_utils
  from tensorflow.python.keras.utils.io_utils import ask_to_proceed_with_overwrite
  from tensorflow.python.platform import tf_logging as logging
  from tensorflow.python.util import nest
  +from tensorflow.python.util.compat import collections_abc
  def extract_model_metrics(model):
  @@ -79,7 +79,8 @@ def model_input_signature(model, keep_original_batch_size=False):
  return None
  input_specs = _enforce_names_consistency(input_specs)
  # Return a list with a single element as the model's input signature.
  - if isinstance(input_specs, collections.Sequence) and len(input_specs) == 1:
  + if isinstance(input_specs,
  + collections_abc.Sequence) and len(input_specs) == 1:
  # Note that the isinstance check filters out single-element dictionaries,
  # which should also be wrapped as a single-element list.
  return input_specs
  