message: Fix positional arg in call test failure in single execution path.
diff: @@ -976,6 +976,8 @@ class Model(network.Network):
  Raises:
  ValueError: In case of invalid user-provided arguments.
  """
  + self._assert_compile_was_called()
  + self._check_call_args('train_on_batch')
  if self._run_distributed:
  outputs = training_v2_utils.train_on_batch(
  self, x, y=y, sample_weight=sample_weight,
  @@ -986,8 +988,6 @@ class Model(network.Network):
  outputs = outputs[0]
  return outputs
  - self._assert_compile_was_called()
  - self._check_call_args('train_on_batch')
  # If at this point we are in the replica context, then it is okay to execute
  # the Eager code path. The expected way to get here is to call `fit` that
  # calls `train_on_batch` on each replica.
  @@ -1069,6 +1069,8 @@ class Model(network.Network):
  Raises:
  ValueError: In case of invalid user-provided arguments.
  """
  + self._assert_compile_was_called()
  + self._check_call_args('test_on_batch')
  if self._run_distributed:
  outputs = training_v2_utils.test_on_batch(
  self, x, y=y, sample_weight=sample_weight,
  @@ -1079,8 +1081,6 @@ class Model(network.Network):
  outputs = outputs[0]
  return outputs
  - self._assert_compile_was_called()
  - self._check_call_args('test_on_batch')
  if (self._distribution_strategy and
  distribution_strategy_context.in_cross_replica_context()):
  raise NotImplementedError('`test_on_batch` is not supported for models '
  