code: public static <K, V> DataLoader<K, V> newMappedDataLoader(MappedBatchLoaderWithContext<K, V> batchLoadFunction) {
          return newMappedDataLoader(batchLoadFunction, null);
      }
docs: Creates new DataLoader with the specified mapped batch loader function and default options
  (batching, caching and unlimited batch size).
  
  @param batchLoadFunction the batch load function to use
  @param <K>               the key type
  @param <V>               the value type
  
  @return a new DataLoader