docs: protected Set<CacheEntryTag> getTags(Element element) {
          final Object key = element.getObjectKey();
          if (key instanceof TaggedCacheEntry) {
              return ((TaggedCacheEntry) key).getTags();
          }
  
          final Object value = element.getObjectValue();
          if (value instanceof TaggedCacheEntry) {
              return ((TaggedCacheEntry) value).getTags();
          }
  
          return null;
      }