TF_OutputList* add_outputs = TF_NewOutputList();
    TF_OutputListSetNumOutputs(add_outputs, 1, status.get());
    ASSERT_EQ(TF_OK, TF_GetCode(status.get())) << TF_Message(status.get());
    // Trace the operation now (create a node in the graph).
    TF_ExecuteOperation(add_op, 2, inputs, add_outputs, s);
    ASSERT_EQ(TF_OK, TF_GetCode(s)) << TF_Message(s);
    TF_DeleteAbstractOp(add_op);