docs: public static MapNameAndKeyPair parseMemcacheKey(String key) {
          key = decodeKey(key, "UTF-8");
          String mapName = DEFAULT_MAP_NAME;
          int index = key.indexOf(':');
          if (index != -1) {
              mapName = MAP_NAME_PREFIX + key.substring(0, index);
              key = key.substring(index + 1);
          }
          return new MapNameAndKeyPair(mapName, key);
      }