code: public static <K, V> Maybe<Map<K, V>> getAll(String key, Class<K> kClazz, Class<V> vClazz) {
          return getAll(CacheService.CACHE_CONFIG_BEAN, key, kClazz, vClazz);
      }
docs: retrival the cached map
  
  @param key    the key
  @param kClazz the key's class
  @param vClazz the values's class
  @param <K>    the generic type of the key
  @param <V>    the generic type of the value
  @return the whole map or null if the key does not exist