docs: private static CmsXmlContainerPage getCache(CmsObject cms, CmsResource resource, boolean keepEncoding) {
  
          if (resource instanceof I_CmsHistoryResource) {
              return null;
          }
          return getCache().getCacheContainerPage(
              getCache().getCacheKey(resource.getStructureId(), keepEncoding),
              cms.getRequestContext().getCurrentProject().isOnlineProject());
      }