docs: private void add2MBR(int[] entrySorting, double[] ub, double[] lb, int index) {
      SpatialComparable currMBR = node.getEntry(entrySorting[index]);
      for(int d = 0; d < currMBR.getDimensionality(); d++) {
        double max = currMBR.getMax(d);
        if(max > ub[d]) {
          ub[d] = max;
        }
        double min = currMBR.getMin(d);
        if(min < lb[d]) {
          lb[d] = min;
        }
      }
    }