code: def testGraphModeWithGradients(self):
      v = resource_variable_ops.ResourceVariable(1.0, name="v")
  
      @polymorphic_function.function
      def step():
          def inner():
              return v * v
  
          return backprop.implicit_grad(inner)()[0][0]
  
      self.assertAllEqual(step(), 2.0)
  
imports: from absl.testing import parameterized
  from tensorflow.python.eager import backprop
  from tensorflow.python.eager import context
  from tensorflow.python.eager.polymorphic_function import polymorphic_function
  from tensorflow.python.framework import config
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import indexed_slices
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import tensor_shape
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import cond
  from tensorflow.python.ops import gradients_impl
  from tensorflow.python.ops import math_ops
  from tensorflow.python.ops import nn_grad
  from tensorflow.python.ops import nn_ops
  from tensorflow.python.ops import resource_variable_ops
  from tensorflow.python.ops import variable_scope
  from tensorflow.python.ops import variables
  from tensorflow.python.ops import while_loop
  from tensorflow.python.platform import test
label_desc: Use image node_id 2 for calling the FunctionGradientsTest obj's underlying member method code with example usage: obj.testGraphModeWithGradients() and returns: backprop, unknown