message: Add custom_training_loop_test for constant input.
diff: @@ -39,6 +39,27 @@ from tensorflow.python.util import nest
  class InputIterationTest(test.TestCase, parameterized.TestCase):
  + @combinations.generate(
  + combinations.combine(
  + distribution=strategy_combinations.all_strategies,
  + mode=["eager"]
  + ))
  + def testConstantNumpyInput(self, distribution):
  +
  + @def_function.function
  + def run(x):
  +
  + def computation(x):
  + return math_ops.square(x)
  +
  + outputs = distribution.experimental_local_results(
  + distribution.experimental_run_v2(computation, args=(x,)))
  + return outputs
  +
  + self.assertAllEqual(
  + constant_op.constant(4., shape=(distribution.num_replicas_in_sync)),
  + run(2.))
  +
  @combinations.generate(
  combinations.combine(
  distribution=strategy_combinations.strategies_minus_tpu,
  