auto graph = std::make_unique<Graph>(OpRegistry::Global());
  TF_ASSERT_OK(root.ToGraph(graph.get()));

  TF_ASSERT_OK(PartiallyDecluster(&graph));

  Node* n_b = FindNodeByName(*graph, "b");
  ASSERT_NE(n_b, nullptr);
  EXPECT_EQ(GetXlaClusterForNode(*n_b), std::nullopt);

  Node* n_c = FindNodeByName(*graph, "c");
  ASSERT_NE(n_c, nullptr);
  EXPECT_EQ(GetXlaClusterForNode(*n_c), std::nullopt);

      /*Inputs*/ {"n_a:float", "n_b:float"},
      /*Outputs*/ {"n_c:float"},
      /*Attribute*/ {},
      // Node info
      {{{kCompilableFunctionNodeName},
        "Add",
        {"n_a", "n_b"},
        {{"T", DT_FLOAT}}}});
  *flib.add_function() = FunctionDefHelper::Define(
      /*Function*/ kUncompilableFunctionName,
      /*Inputs*/ {"n_a:float"},
      /*Outputs*/ {"n_c_uncompilable:float"},