code: protected final LocalDate createLocalDate(final String dateString) {
          if (dateString == null || dateString.isEmpty()) {
              return null;
          }
          final DateParser parser = new DateParser(dateString);
          return new LocalDate(parser.getEstimateCalendar());
      }
docs: Create a LocalDate from the given date string. Returns null
  for an empty or null date string.
  
  @param dateString the date string
  @return the new LocalDate