ASSERT_TRUE(nodes.find(node_def.name()) != nodes.end())
          << "Got unexpected node: " << node_def.name()
          << " in fdef: " << fdef.DebugString();
    }
  }

  void VerifyFDefInputs(const tensorflow::FunctionDef& fdef,
                        const std::vector<IOSpec>& inputs) {
    const OpDef& signature = fdef.signature();
    ASSERT_EQ(inputs.size(), signature.input_arg_size());