public Node remove(Node node) {
			if (null == node) return node;
			if (head == node && head.next == head) {head = null;}
			else {
				node.prevous.next = node.next;
				node.next.prevous = node.prevous;
				if (head == node) {
					head = node.next;
				}
				node.next = null;
				node.prevous = null;
			}
			return node;
		}