import java.util.*;

class Generisk<K, V> implements Iterable<K> {
    HashMap<K, V> hashMap;

    public Generisk() {
        hashMap = new HashMap<>();
    }

    public void put(K key, V value) {
        hashMap.put(key, value);
    }

    public V take(K key) {
        return hashMap.remove(key);
    }

    public boolean isEmpty() {
        return hashMap.isEmpty();
    }

    // Itererer gjennom n?klene i hashmappet
    public Iterator<K> iterator() {
        // Anonym klasse som implementerer Iterator-interfacet
        return new Iterator<K>(){
            @SuppressWarnings("unchecked")
            K[] keys = (K[]) hashMap.keySet().toArray();
            int teller = 0;

            public boolean hasNext() {
                return teller < keys.length;
            }

            public K next() {
                return keys[teller++];
            }
        };
    }

    public static void main(String[] args) {
        Generisk<String, Integer> hm = new Generisk<>();

        hm.put("Ting1", 100);
        hm.put("Ting2", 220);
        hm.put("Ting3", null);
        for (String key : hm) {
            System.out.println(key);
        }


    }
}