code: @Override
    public void parseStringValue(String value) {
      LocalDate d = this.formatter.parseLocalDate(value);
      // The parser allows dates on the format YY-MM-DD (commonly used in Sweden), but we require 4 digits for year.
      if (d.getCenturyOfEra() == 0) {
        throw new IllegalArgumentException("Illegal date format - YYYY-MM-DD is required");
      }
      this.setDate(d);
    }
docs: {@inheritDoc}