code: @Override
      public D move(
          CalendarControl<D> control,
          int direction
      ) {
          D date = control.pageDateProperty().getValue();
          D result;
  
          switch (control.viewIndexProperty().get()) {
              case NavigationBar.MONTH_VIEW:
                  result = date.plus(direction, this.getMonthsUnit());
                  break;
              case NavigationBar.YEAR_VIEW:
                  result = date.plus(direction, this.getYearsUnit());
                  break;
              case NavigationBar.BIRD_VIEW:
                  result = date.plus(Math.multiplyExact(direction, 10), this.getYearsUnit());
                  break;
              default:
                  throw new IllegalStateException("Invalid view: " + control.viewIndexProperty().getValue());
          }
  
          return result;
      }
docs: ~ Methoden ----------------------------------------------------------