Let's implement get! All get needs to do is find a key in this.cache. If found, we moveToHead to let keep it as the most recently used key, and return it. Otherwise, we return -1.

1get(key) {
2	const node = this.cache[key];
3	if (!node) {
4	    return -1;
5	}
6	this.moveToHead(node);
7	return node.val;
8};