Function diff_user_quotas 

pub fn diff_user_quotas(
    current: &UserQuotaConfig,
    desired: &UserQuotaConfig,
) -> Vec<QuotaOp>

Pure function.

It diffs the desired key-set against the current key-set and produces the minimal (set, remove) op stream. Floats compare bit-equal, so it does not re-issue a no-op Set with the same value.