@Test
public void testGetFreeSpace() {

  AbstractCacheWrapper uut = new AbstractCacheWrapper(entries, storageAll,
      IDataCache.STD_MAX_CACHE_SIZE, predicate -> true);
  assertEquals(IDataCache.STD_MAX_CACHE_SIZE, uut.getFreeSpace());
  uut.cacheData(c0);
  assertEquals(IDataCache.STD_MAX_CACHE_SIZE - c0.getByteSize(), uut.getFreeSpace());
  uut.cacheData(c1);
  assertEquals(IDataCache.STD_MAX_CACHE_SIZE - (c0.getByteSize() + c1.getByteSize()),
      uut.getFreeSpace());
}