docs: public List<Map<String, INDArray>> output(MultiDataSetIterator iterator, String... outputs){
          Preconditions.checkState(trainingConfig != null, "Training config has not been set");
  
          List<String> reqVars;
  
          if(outputs != null){
              reqVars = Arrays.asList(outputs);
          } else {
              reqVars = outputs();
          }
  
          List<Map<String, INDArray>> predictions = new ArrayList<>();
  
          if(!iterator.hasNext() && iterator.resetSupported())
              iterator.reset();
  
          while(iterator.hasNext()){
              MultiDataSet ds = iterator.next();
              Map<String,INDArray> placeholderMap = toPlaceholderMap(ds);
  
              predictions.add(exec(placeholderMap, reqVars));
          }
  
          return predictions;
      }