message: Add test to verify assign().op doesn't throw
diff: @@ -361,6 +361,19 @@ class AutoCastVariableTest(test.TestCase, parameterized.TestCase):
  dtypes.float16):
  self.assertAllClose(5., self.evaluate(run_assign()))
  + @combinations.generate(maybe_distribute)
  + def test_assign_op(self, distribution):
  + with distribution.scope():
  + x = get_var(0., dtypes.float32)
  + x = autocast_variable.create_autocast_variable(x)
  +
  + @def_function.function
  + def func():
  + self.assertIsNotNone(x.assign(1.0).op)
  + self.assertIsNotNone(x.assign_add(1.0).op)
  + self.assertIsNotNone(x.assign_sub(1.0).op)
  + func()
  +
  @combinations.generate(maybe_distribute)
  def test_tf_function_control_dependencies(self, distribution):
  if not context.executing_eagerly():
  