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);

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

      "CompilableFn", {"n_a:float", "n_b:float"}, {"n_c:float"}, {},
      {{{"n_c"}, "Add", {"n_a", "n_b"}, {{"T", DT_FLOAT}}}});
  FunctionDef uncompilable =
      FunctionDefHelper::Define("UncompilableFn", {"n_a:float"}, {"n_c:float"},
                                {}, {{{"n_c"}, "UncompilableUnary", {"n_a"}}});

  FunctionDefLibrary flib;
  *flib.add_function() = compilable;

constexpr char kFunctionalCaseNodeName[] = "Case";
constexpr char kFunctionalWhileNodeName[] = "While";
constexpr char kCompilableFunctionName[] = "CompilableFn";
constexpr char kCompilableFunctionNodeName[] = "n_c";
constexpr char kUncompilableFunctionName[] = "UncompilableFn";
constexpr char kUncompilableFunctionNodeName[] = "n_c_uncompilable";
constexpr char kUncompilableFunctionTwoName[] = "UncompilableFnTwo";