message: Acknowledges tape in graph mode doesn't like unknown shapes
diff: @@ -31,7 +31,6 @@ from tensorflow.python.framework import ops
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import control_flow_ops
  -from tensorflow.python.ops import gradients
  from tensorflow.python.ops import list_ops
  from tensorflow.python.ops import math_ops
  from tensorflow.python.ops import state_ops
  @@ -266,13 +265,10 @@ class ListOpsTest(test_util.TensorFlowTestCase):
  c = constant_op.constant([1.0, 2.0])
  tape.watch(c)
  l = list_ops.tensor_list_from_tensor(c, element_shape=scalar_shape())
  - c2 = list_ops.tensor_list_stack(l, element_dtype=dtypes.float32)
  + c2 = list_ops.tensor_list_stack(
  + l, element_dtype=dtypes.float32, num_elements=2)
  result = c2 * 2.0
  - if context.in_eager_mode():
  - # TODO(b/77609620): Fix this in graph mode.
  grad = tape.gradient(result, [c])[0]
  - else:
  - grad = gradients.gradients(result, [c])[0]
  self.assertAllEqual(self.evaluate(grad), [2.0, 2.0])
  @test_util.run_in_graph_and_eager_modes()
  