Comment # 15 on bug 1191260 from Michal Suchanek

It still stands.

You claim you remove redundancy but is_supported needs to detect which
certificate management is preset as does enroll and delete.

So is_supported is completely redundant.

But the worse problem is that whatever piece of code you are changing you have
to be aware of

if ! is_supported; then 
    exit 0
fi

 - the code is no longer local.