@Override
    public void removeHandle(final K key) {
        Optional.ofNullable(key).ifPresent(cached::remove);
    }
@Test
    public void removeHandle() {
        commonHandleCache.cachedHandle(MOCK_KEY, MOCK_VALUE);
        assert cachedMockMap.size() == 1;
        commonHandleCache.removeHandle(MOCK_KEY);
        assert cachedMockMap.isEmpty();
    }