docs: public static int lastWhitespaceIn(String source) {
  
          if (CmsStringUtil.isEmpty(source)) {
              return -1;
          }
          int pos = -1;
          for (int i = source.length() - 1; i >= 0; i--) {
              if (Character.isWhitespace(source.charAt(i))) {
                  pos = i;
                  break;
              }
          }
          return pos;
      }