const lruCache = new LRU(3);
lruCache.write('a', 123);
lruCache.write('b', 456);
lruCache.write('c', 789); // lru is 'a'
lruCache.read('a'); // lru is 'b'

// Now max limit 3 is reached. Let's add a new element
lruCache.write('d', 0); // lru 'b' is removed
console.log(lruCache);