docs: public <K> JavaPairRDD<K, INDArray[]> feedForwardWithKey(JavaPairRDD<K, INDArray[]> featuresData, int batchSize) {
          return featuresData.mapPartitionsToPair(new GraphFeedForwardWithKeyFunction<K>(sc.broadcast(network.params()),
                          sc.broadcast(conf.toJson()), batchSize));
      }