message: Add a sanity check in multi worker callback test to ensure training for an additional epoch gives different result.
diff: @@ -283,6 +283,14 @@ class KerasMultiWorkerCallbackTest(test_base.IndependentWorkerTestBase,
  history_after_one_more_epoch.history,
  history_after_model_restoring_and_one_more_epoch.history)
  + history_one_more_epoch_without_model_restoring = model.fit(
  + x=train_ds, epochs=1, steps_per_epoch=steps)
  +
  + # Ensuring training for another epoch gives different result.
  + test_obj.assertNotAllClose(
  + history_after_model_restoring_and_one_more_epoch.history,
  + history_one_more_epoch_without_model_restoring.history)
  +
  @staticmethod
  def callableForTestUnmatchedModelFile(model, test_obj, train_ds, num_epoch,
  steps, strategy, saving_filepath):
  