message: Remove the unused _like_rnncell function and prefer the assert_like_rnncell
diff: @@ -54,16 +54,6 @@ from tensorflow.python.util.tf_export import tf_export
  _BIAS_VARIABLE_NAME = "bias"
  _WEIGHTS_VARIABLE_NAME = "kernel"
  -
  -# TODO(jblespiau): Remove this function when we are sure there are no longer
  -# any usage (even if protected, it is being used). Prefer assert_like_rnncell.
  -def _like_rnncell(cell):
  - """Checks that a given object is an RNNCell by using duck typing."""
  - conditions = [hasattr(cell, "output_size"), hasattr(cell, "state_size"),
  - hasattr(cell, "zero_state"), callable(cell)]
  - return all(conditions)
  -
  -
  # This can be used with self.assertRaisesRegexp for assert_like_rnncell.
  ASSERT_LIKE_RNNCELL_ERROR_REGEXP = "is not an RNNCell"
  