auto x1 = ops::Placeholder(root.WithOpName("x1"), DT_FLOAT);
  auto x2 = ops::Placeholder(root.WithOpName("x2"), DT_FLOAT);
  auto const_guarantee_x2 =
      ops::GuaranteeConst(root.WithOpName("const_guarantee_x2"), x2);
  auto const_guarantee_x1 =
      ops::GuaranteeConst(root.WithOpName("const_guarantee_x1"), x1);
  auto add1 =
      ops::Add(root.WithOpName("add1"), const_guarantee_x1, const_guarantee_x2);