LRU Cache with LinkedHashMap

import java.util.*;

public class LruCache<K, V> extends LinkedHashMap<K, V> {
    private final int capacity;

    public LruCache(int capacity) {
        super(16, 0.75f, true);                              // true = order by access, not by insertion
        this.capacity = capacity;
    }

    // Called after every put: returning true removes the least recently used entry.
    @Override
    protected boolean removeEldestEntry(Map.Entry<K, V> eldest) {
        return size() > capacity;
    }

    public static void main(String[] args) {
        LruCache<String, Integer> cache = new LruCache<>(3);
        cache.put("a", 1);
        cache.put("b", 2);
        cache.put("c", 3);
        cache.get("a");                                      // "a" is now the most recently used
        cache.put("d", 4);                                   // over capacity: "b" is evicted

        System.out.println(cache.keySet());                  // [c, a, d]
        System.out.println(cache.containsKey("b"));          // false
        System.out.println(cache.get("c"));                  // 3
        System.out.println(cache.keySet());                  // [a, d, c]
    }
}