code: private static Weekmodel getDefaultWeekmodel() {
  
          return Weekmodel.of(Weekday.SUNDAY, 1, Weekday.SUNDAY, Weekday.SUNDAY); // historic condition
  
      }
docs: /*[deutsch]
  <p>Ermittelt das Standardwochenmodell dieses Kalenders. </p>
  
  <p>Dieser Kalender startet historisch am Sonntag. </p>
  
  @return  Weekmodel