docs: public static int getStringCharacterIndex(String s, int columnIndex) {
          int index = 0;
          int counter = 0;
          while(counter < columnIndex) {
              if(isCharCJK(s.charAt(index++))) {
                  counter++;
                  if(counter == columnIndex) {
                      return index - 1;
                  }
              }
              counter++;
          }
          return index;
      }