public void removeLast() {
		ListElement tmp = head;
		if (head == null) {
			return;
		}
		if (head.rest() == null) {
			head = null;
			size--;
			return;
		}
		while (tmp.rest().rest() != null) {
			tmp = tmp.rest();
		}
		tmp.el2 = null;
		size--;
	}