### Question:
SoftCacheLongKeyMap { public Object remove(long key) { Entry entry = (Entry)map.remove(key); if (entry != null) { entry.delete(); return entry.get(); } return null; } SoftCacheLongKeyMap(int cacheSize); Object put(long key, Object value); Object get(long key); int size(); void clear(); boolean isEmpty(); boolean containsKey(long key); Object remove(long key); long[] getKeys();  }### Answer:
@Test public void testRemove() { cache = new SoftCacheLongKeyMap(10); cache.put(0, "aaa"); cache.put(1, "bbb"); cache.put(2, "ccc"); cache.put(3, "ddd"); cache.remove(1); cache.remove(0); cache.remove(3); cache.remove(2); assertEquals(0, cache.size()); cache.put(5, "zzz"); assertEquals(1, cache.size()); cache.remove(5); assertEquals(0, cache.size()); }