AbstractCache implements IDataCache<T> { @Override public boolean dataIsStorable(T data) { return cachedStorage.dataIsStorable(data); } AbstractCache(S entries, IDataStorage<T> cachedStorage, long maxCacheSize,
      Predicate<T> cachingRule); @Override long getMaxCacheSize(); @Override boolean setMaxCacheSize(long maxCacheSize); @Override long getCurrentCacheSize(); @Override long getFreeSpace(); @Override boolean hasStorageFor(long size); @Override void cacheData(T data); @Override void uncacheData(T data); @Override boolean dataIsCachable(T data); @Override boolean dataIsInCache(long id); @Override void clearCache(); @Override boolean dataExists(long id); @Override T loadData(long id); @Override boolean saveData(T data); @Override boolean dataIsStorable(T data); @Override boolean deleteData(T data);  }
@Test public void testDataIsStorable() { AbstractCacheWrapper uut = new AbstractCacheWrapper(entries, storageAll, 20000, predicate -> true); assertTrue(uut.dataIsStorable(c0)); assertTrue(uut.dataIsStorable(null)); entries.clear(); uut = new AbstractCacheWrapper(entries, storageNone, 20000, predicate -> true); assertFalse(uut.dataIsStorable(c0)); assertFalse(uut.dataIsStorable(null)); }