code: public CacheConfigurationBuilder<K, V> withLoaderWriter(CacheLoaderWriter<K, V> loaderWriter) {
      return addOrReplaceConfiguration(new DefaultCacheLoaderWriterConfiguration(requireNonNull(loaderWriter, "Null loaderWriter")));
    }
docs: Adds a {@link CacheLoaderWriter} to the configured builder.
  <p>
  Configuration of a {@link CacheLoaderWriter} is what enables cache-through patterns.
  
  @param loaderWriter the loaderwriter to use
  @return a new builder with the added loaderwriter configuration