// directly to create the back edge.
  NodeBuilder::NodeOut enter_input(enter_output.node(), enter_output.index());

  const int next_output_index = 0;
  DataType dtype = enter_output.node()->output_type(0);
  NodeBuilder::NodeOut next_input(NextIterationName(scope, loop_var_idx),
                                  next_output_index, dtype);

  std::vector<NodeBuilder::NodeOut> input_list({enter_input, next_input});

  inner_params.body_outputs[0] = {inner_input1_add, 0};

  // Finalize inner graph
  TF_Output inner_outputs[2] = {{nullptr, -1}};
  TF_FinishWhile(&inner_params, s_, inner_outputs);
  ASSERT_EQ(TF_OK, TF_GetCode(s_)) << TF_Message(s_);

  TF_Operation* input1_add =
      Add(params_->body_inputs[0], inner_outputs[1], params_->body_graph, s_);
  ASSERT_EQ(TF_OK, TF_GetCode(s_)) << TF_Message(s_);

  VerifyFDefInputs(fdef, M({{"feed1"}, {"feed2"}}));
  VerifyFDefOutputs(fdef, M({{"test_loop_exit"}}));
  VerifyFDefEdges(fdef,
                  {{"feed1", "test_loop/Enter:0"},
                   {"test_loop/Enter:output:0", "test_loop/Merge:0"},
                   {"test_loop/Merge:output:0", "test_loop/Switch:0"},
                   {"test_loop/Switch:output_false:0", "test_loop/Exit:0"},