code: void exit() {
  
          if (m_changed) {
              CmsConfirmationDialog.show(
                  CmsVaadinUtils.getMessageText(org.opencms.ui.apps.Messages.GUI_EDITOR_CLOSE_CAPTION_0),
                  CmsVaadinUtils.getMessageText(org.opencms.ui.apps.Messages.GUI_EDITOR_CLOSE_TEXT_0),
                  new Runnable() {
  
                      public void run() {
  
                          exitInternal();
                      }
                  });
          } else {
              exitInternal();
          }
  
      }
docs: Exits the editor without saving.<p>
  Will ask to confirm exit on changed contents.<p>