### Question:
ConcurrentLongHashMap { public V remove(long key) { long h = hash(key); return getSection(h).remove(key, null, (int) h); } ConcurrentLongHashMap();  ConcurrentLongHashMap(int expectedItems);  ConcurrentLongHashMap(int expectedItems, int concurrencyLevel); long size(); long capacity(); boolean isEmpty(); V get(long key); boolean containsKey(long key); V put(long key, V value); V putIfAbsent(long key, V value); V computeIfAbsent(long key, LongFunction<V> provider); V remove(long key); boolean remove(long key, Object value); int removeIf(LongObjectPredicate<V> predicate); void clear(); void forEach(EntryProcessor<V> processor); List<Long> keys(); List<V> values();  }### Answer:
@Test public void testRemove() { ConcurrentLongHashMap<String> map = new ConcurrentLongHashMap<>(); assertTrue(map.isEmpty()); assertNull(map.put(1, "one")); assertFalse(map.isEmpty()); assertFalse(map.remove(0, "zero")); assertFalse(map.remove(1, "uno")); assertFalse(map.isEmpty()); assertTrue(map.remove(1, "one")); assertTrue(map.isEmpty()); }