docs: @Override
      public int compare(HashMap m1, HashMap m2) {
          double val1;
          double val2;
          for (String sortId : sortIds) {
              val1 = getValue(m1, sortId);
              val2 = getValue(m2, sortId);
              if (val1 > val2) {
                  return decVal;
              } else if (val1 < val2) {
                  return ascVal;
              }
          }
          return 0;
      }