docs: public static Pair<INDArray, INDArray> mergeFeatures(INDArray[][] featuresToMerge, INDArray[][] featureMasksToMerge,
                      int inOutIdx) {
          Pair<INDArray[], INDArray[]> p = selectColumnFromMDSData(featuresToMerge, featureMasksToMerge, inOutIdx);
          return mergeFeatures(p.getFirst(), p.getSecond());
      }