private void clearInternal() {
        // remove all transient permissions added by this attachment
        User user = this.permissible.getUser();
        user.removeIf(DataType.TRANSIENT, null, n -> n.getMetadata(TRANSIENT_SOURCE_KEY).orElse(null) == this, false);
    }
Hooks this attachment with the parent {@link User} instance.
nukkit/src/main/java/me/lucko/luckperms/nukkit/inject/permissible/LuckPermsPermissionAttachment.java