public synchronized Linkable removeFromTail() {
		if (head == null)
			return null;
		Linkable p = head, q = null, next = head.getNext();
		if (next == null) {
			head = null;
			return p;
		}
		while ((next = p.getNext()) != null) {
			q = p;
			p = next;
		}
		q.setNext(null);
		return p;
	}