docs: CmsFlexCacheKey setCmsCacheKey(String resourcename, String cacheDirectives, boolean online)
      throws CmsFlexCacheException {
  
          m_key = new CmsFlexCacheKey(resourcename, cacheDirectives, online);
          if (m_key.hadParseError()) {
              // We throw the exception here to make sure this response has a valid key (cache=never)
              throw new CmsFlexCacheException(
                  Messages.get().container(
                      Messages.LOG_FLEXRESPONSE_PARSE_ERROR_IN_CACHE_KEY_2,
                      cacheDirectives,
                      resourcename));
          }
          return m_key;
      }