message: Add shape test for ragged reduce_sum.
diff: @@ -321,6 +321,13 @@ class RaggedReduceOpsTest(test_util.TensorFlowTestCase,
  reduced = ragged_reduce_op(rt_input, axis)
  self.assertAllEqual(reduced, expected)
  + def testReduceKeepsInnerDimensionShape(self):
  + # Test for bug [b/139823356].
  + rt = ragged_factory_ops.constant([[[[1, 1]]]], ragged_rank=2)
  + self.assertEqual(rt.shape.as_list(), [1, None, None, 2])
  + reduced = ragged_math_ops.reduce_sum(rt, axis=2)
  + self.assertEqual(reduced.shape.as_list(), [1, None, 2])
  +
  def assertEqualWithNan(self, actual, expected):
  """Like assertEqual, but NaN==NaN."""
  self.assertTrue(
  