// Workaround for not being able to initialize empty map using {}
  std::unordered_set<string> empty_;
};

TEST_F(CApiFunctionTest, OneOp_ZeroInputs_OneOutput) {
  /*
   *                constant
   *                   |
   *                   v
   */
  // Define
  TF_Operation* c = ScalarConst(10, func_graph_, s_, "scalar10");
  Define(-1, {}, {}, {c}, {});

  // Use, run, and verify

    feed2_ = Placeholder(graph_, s_, "feed2");
    ASSERT_EQ(TF_OK, TF_GetCode(s_)) << TF_Message(s_);

    constant_ = ScalarConst(10, graph_, s_);
    ASSERT_EQ(TF_OK, TF_GetCode(s_)) << TF_Message(s_);

    desc_ = TF_NewOperation(graph_, "AddN", "add");
    TF_Output inputs[] = {{feed1_, 0}, {constant_, 0}};
    TF_AddInputList(desc_, inputs, TF_ARRAYSIZE(inputs));
  }

  ~CApiColocationTest() override {