docs: public I_CmsContainerpageServiceAsync getContainerpageService() {
  
          if (m_containerpageService == null) {
              m_containerpageService = GWT.create(I_CmsContainerpageService.class);
              String serviceUrl = CmsCoreProvider.get().link("org.opencms.ade.containerpage.CmsContainerpageService.gwt");
              ((ServiceDefTarget)m_containerpageService).setServiceEntryPoint(serviceUrl);
          }
          return m_containerpageService;
      }