docs: public INDArray[] output(MultiDataSetIterator iterator){
          List<INDArray[]> outputs = new ArrayList<>();
          while(iterator.hasNext()){
              MultiDataSet next = iterator.next();
              INDArray[] out = output(false, next.getFeatures(), next.getFeaturesMaskArrays(), next.getLabelsMaskArrays());
              outputs.add(out);
          }
          INDArray[][] arr = outputs.toArray(new INDArray[outputs.size()][0]);
          return DataSetUtil.mergeFeatures(arr, null).getFirst();
      }