docs: protected void registerEventListener() {
  
          OpenCms.addCmsEventListener(
              this,
              new int[] {
                  I_CmsEventListener.EVENT_RESOURCE_AND_PROPERTIES_MODIFIED,
                  I_CmsEventListener.EVENT_RESOURCES_AND_PROPERTIES_MODIFIED,
                  I_CmsEventListener.EVENT_RESOURCE_MODIFIED,
                  I_CmsEventListener.EVENT_RESOURCES_MODIFIED,
                  I_CmsEventListener.EVENT_RESOURCE_MOVED,
                  I_CmsEventListener.EVENT_RESOURCE_DELETED,
                  I_CmsEventListener.EVENT_PUBLISH_PROJECT,
                  I_CmsEventListener.EVENT_CLEAR_CACHES,
                  I_CmsEventListener.EVENT_CLEAR_ONLINE_CACHES,
                  I_CmsEventListener.EVENT_CLEAR_OFFLINE_CACHES});
      }