synchronized LRUCacheEntry get(final Bytes key) {
        if (key == null) {
            return null;
        }

        final LRUNode node = getInternal(key);
        if (node == null) {
            return null;
        }
        updateLRU(node);
        return node.entry;
    }
@Test
    public void shouldReturnNullIfKeyIsNull() {
        assertNull(cache.get(null));
    }