public CacheSpec<K, V> loadingFunction(Function<K, V> loadingFunction) {
      this.cacheFunction = loadingFunction;
      return this;
   }
public CacheSpec < K , V > loadingFunction ( Function < K , V > loadingFunction ) { this . cacheFunction = loadingFunction ; return this ; }
Loading function cache spec.

@param loadingFunction the loading function
@return the cache spec