docs: private void checkSelection(boolean suppressEvent) {
          Dateitem selectedItem = getSelectedItem();
          
          if (selectedItem == null) {
              selectedItem = lastSelectedItem;
              setSelectedItem(selectedItem);
          } else if (selectedItem != customItem && lastSelectedItem != selectedItem) {
              lastSelectedItem = selectedItem;
              
              if (!suppressEvent) {
                  EventUtil.send(new Event(ON_SELECT_RANGE, this));
              }
          }
          
          updateSelection();
      }