Question about relative robustness

Hi I have a question about relative robustness.
There is a function of "relative_robustness_helper" in eval_scripts/robustness.py.
It may be my misunderstanding, but that function is correct?
I think it's necessary to compare with 'LF' result, but it doesn't do it.
(I checked the paper and there is some explanation about it but I think it's not same to code)