message: fixed KeyError issue for tf.Module
diff: @@ -87,7 +87,7 @@ def _get_attrs_items(obj):
  def _sorted(dict_):
  """Returns a sorted list of the dict keys, with error if keys not sortable."""
  try:
  - return sorted(dict_)
  + return sorted(dict_.keys())
  except TypeError:
  raise TypeError("nest only supports dicts with sortable keys.")
  