docs: @Override
      public double value(int indexAttribute) {
          int location = locateIndex(indexAttribute);
          //return location == -1 ? 0 : this.attributeValues[location];
          //      int index = locateIndex(attIndex);
          if ((location >= 0) && (indexValues[location] == indexAttribute)) {
              return attributeValues[location];
          } else {
              return 0.0;
          }
      }