/* nreturn_nodes */ 1, &cond_output));
        *output = cond_output[0];
        return absl::OkStatus();
      };

  // 'body_fn' copies the body graph into the parent graph.
  tensorflow::ops::BodyGraphBuilderFn body_fn =
      [params, parent, num_loop_vars](
          const tensorflow::Scope& scope,
          const std::vector<tensorflow::Output>& inputs,

  auto cond_fn =
      symbol_table.lookupNearestSymbolFrom<func::FuncOp>(*this, getCondAttr());
  auto body_fn =
      symbol_table.lookupNearestSymbolFrom<func::FuncOp>(*this, getBodyAttr());
  if (!cond_fn) {
    return emitOpError("cond refers to an undefined function : ") << getCond();
  }
  if (!body_fn) {
    return emitOpError("body refers to an undefined function : ") << getBody();
  }

  TF_RET_CHECK(n->IsWhileNode());

  // Check if there is any lifted args in body function.
  NameAttrList body_func;
  TF_RETURN_IF_ERROR(GetNodeAttr(n->def(), "body", &body_func));
  const FunctionDef* body_function_def = fld->Find(body_func.name());
  TF_RET_CHECK(body_function_def);

  if (!HasLiftedArgs(*body_function_def)) {
    return absl::OkStatus();
  }