Schibsted Konkurs

public class Cache<K, V> {

private Map<K, __________<V>> internalCache = new HashMap<>();

    public V get(K key, ___________<V> calledWhenAbsent) throws Exception {
        _____________<V> something = internalCache.get(key);
        V result;
        if (something == null || something.get() == null) {
            result = calledWhenAbsent.call();
            internalCache.put(key, new _____________<V>(result));
        } else {
            result = something.get();
        }
        return result;
    }

}