@Override
        public boolean addAll(@NonNull Collection<? extends PermissionAttachment> c) {
            boolean modified = false;
            for (PermissionAttachment e : c) {
                if (add(e)) {
                    modified = true;
                }
            }
            return modified;
        }
A fake list to be injected into the superclass. This implementation simply
proxies calls back to this permissible instance.

Some (clever/dumb??) plugins attempt to add/remove/query attachments using reflection.

An instance of this map is injected into the super instance so these plugins continue
to work with LuckPerms.
bukkit/src/main/java/me/lucko/luckperms/bukkit/inject/permissible/LuckPermsPermissible.java