docs: protected static String listToCommaDelimitedString(List<String> stringList) {
          if (stringList == null) {
              return "";
          }
          StringBuilder result = new StringBuilder();
          for (Iterator<String> it = stringList.iterator(); it.hasNext();) {
              Object element = it.next();
              if (element != null) {
                  result.append(element);
                  if (it.hasNext()) {
                      result.append(", ");
                  }
              }
          }
          return result.toString();
      }