@Override
    public synchronized LPProxiedSubject sponge() {
        if (this.spongeSubject == null) {
            this.spongeSubject = ProxyFactory.toSponge(this);
        }
        return this.spongeSubject;
    }
Implements {@link LPSubject} for a {@link PermissionHolder}.
sponge/src/main/java/me/lucko/luckperms/sponge/service/model/permissionholder/PermissionHolderSubject.java