public void remove(final Superiority sup) {
		Set<Superiority> list = superiors.get(sup.getSuperior());
		if (null != list) {
			if (list.remove(sup)) superiorityCount--;
			if (list.size() == 0) superiors.remove(sup.getSuperior());
		}

		list = inferiors.get(sup.getInferior());
		if (null != list) {
			list.remove(sup);
			if (list.size() == 0) inferiors.remove(sup.getInferior());
		}
	}