### Question:
SelectableConcurrentHashMap { public Element get(Object key) { int hash = hash(key.hashCode()); return segmentFor(hash).get(key, hash); } SelectableConcurrentHashMap(PoolAccessor poolAccessor, boolean elementPinningEnabled, int initialCapacity, float loadFactor, int concurrency, final long maximumSize, final RegisteredEventListeners cacheEventNotificationService); void setMaxSize(final long maxSize); Element[] getRandomValues(final int size, Object keyHint); Object storedObject(Element e); int quickSize(); boolean isEmpty(); int size(); int pinnedSize(); ReentrantReadWriteLock lockFor(Object key); ReentrantReadWriteLock[] locks(); Element get(Object key); boolean containsKey(Object key); boolean containsValue(Object value); Element put(Object key, Element element, long sizeOf); Element putIfAbsent(Object key, Element element, long sizeOf); Element remove(Object key); boolean remove(Object key, Object value); void clear(); void unpinAll(); void setPinned(Object key, boolean pinned); boolean isPinned(Object key); Set<Object> keySet(); Collection<Element> values(); Set<Entry<Object, Element>> entrySet(); boolean evict(); void recalculateSize(Object key); Set pinnedKeySet();  }### Answer:
@Test public void testReturnsPinnedKeysThatArePresent() { assertThat(map.get(1), notNullValue()); assertThat(map.get(2), notNullValue()); assertThat(map.get(3), notNullValue()); assertThat(map.get(4), notNullValue()); }
@Test public void testDoesNotReturnsPinnedKeysThatAreNotPresent() { assertThat(map.get(0), nullValue()); assertThat(map.get(5), nullValue()); }