code: private Component createProjectChoice() {
          DropDownChoice<String> dropDownChoice = new DropDownChoice<String>("projectChoice", new IModel<String>() {
              
              private static final long serialVersionUID = -5776062054709043273L;
  
              @Override
              public String getObject() {
                  return getSessionContextId();
              }
  
              @Override
              public void setObject(String object) {
                  ContextHolder.get().setCurrentContextId(object);
              }
  
              @Override
              public void detach() {
              }
          }, getAvailableContexts()) {
  
              private static final long serialVersionUID = 1L;
  
              @Override
              protected boolean wantOnSelectionChangedNotifications() {
                  return true;
              }
  
              @Override
              protected void onModelChanged() {
                  setResponsePage(SendEventPage.this.getClass());
              }
  
          };
          return dropDownChoice;
      }
docs: TODO: OPENENGSB-3272: Extract this into an own component