SpongeGenericsIdea

class SpongeGenericsIdea {

    interface EntityType<E extends Entity<?>> {
    }

    interface Entity<E extends Entity<?>> {
        EntityType<E> getType();
    }

    interface Creeper extends Entity<Creeper> {
    }

    public void foo() {
        Creeper c = null;
        EntityType<Creeper> type = c.getType();
    }
}