code: public void formatUnits(List<UnitValue> values, StringBuilder destination, UnitFormatOptions options) {
      int size = values.size();
      for (int i = 0; i < size; i++) {
        if (i > 0) {
          destination.append(' ');
        }
        formatUnit(values.get(i), destination, options);
      }
    }
docs: Format a sequence of unit values.