public void insertEnd(int red, int green, int blue, Object runlength) {
		if (size == 0) {
			setHead(tail = new SListNode((short) red, (short) green,
					(short) blue, runlength, null));
		} else {
			tail.next = new SListNode((short) red, (short) green, (short) blue,
					runlength, null);
			tail = tail.next;
		}
		size++;
	}