@Override
        public Boolean get(Object key) {
            // just proxy
            return LuckPermsPermissionAttachment.this.perms.get(key);
        }
A fake map to be injected into the superclass. This implementation simply
proxies calls back to this attachment instance.

Some (clever/dumb??) plugins attempt to modify attachment permissions using reflection
to get around the slow bukkit behaviour in the base PermissionAttachment implementation.

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/LuckPermsPermissionAttachment.java