code: static public String localDateToString(LocalDate date, String emptyDateString) {
          return (date == null) ? emptyDateString : date.toString();
      }
docs: localDateToString, This returns the supplied date in the ISO-8601 format (uuuu-MM-dd). For
  any CE years that are between 0 and 9999 inclusive, the output will have a fixed length of 10
  characters. Years before or after that range will output longer strings. If the date is null,
  this will return the value of emptyDateString.