### Question:
HMapKI implements MapKI<K>, Cloneable, Serializable { @Override public void increment(K key) { if (this.containsKey(key)) { this.put(key, this.get(key) + 1); } else { this.put(key, 1); } } @SuppressWarnings("unchecked")  HMapKI(int initialCapacity, float loadFactor);  HMapKI(int initialCapacity); @SuppressWarnings("unchecked")  HMapKI();  HMapKI(MapKI<? extends K> m); @Override int size(); @Override boolean isEmpty(); @Override int get(K key); @Override boolean containsKey(K key); @Override int put(K key, int value); @Override void putAll(MapKI<? extends K> m); @Override int remove(K key); @Override void clear(); @Override boolean containsValue(int value); @SuppressWarnings("unchecked") @Override Object clone(); @Override Set<K> keySet(); @Override Collection<Integer> values(); @Override Set<MapKI.Entry<K>> entrySet(); @Override String toString(); @Override void plus(MapKI<K> m); @Override long dot(MapKI<K> m); @Override void increment(K key); @Override void increment(K key, int value); @SuppressWarnings("unchecked") MapKI.Entry<K>[] getEntriesSortedByValue(); MapKI.Entry<K>[] getEntriesSortedByValue(int n); @SuppressWarnings("unchecked") MapKI.Entry<K>[] getEntriesSortedByKey(); MapKI.Entry<K>[] getEntriesSortedByKey(int n);  }### Answer:
@Test public void testIncrement() { HMapKI<String> m = new HMapKI<String>(); assertEquals(0, m.get("one")); m.increment("one"); assertEquals(1, m.get("one")); m.increment("one", 5); m.increment("two", 0); m.increment("three", 2); assertEquals(6, m.get("one")); assertEquals(0, m.get("two")); assertEquals(2, m.get("three")); }