docs: private CmsResource findReferencingPage(CmsResource source) throws CmsException {
  
          List<CmsRelation> relationsToFile = m_cms.readRelations(
              CmsRelationFilter.relationsToStructureId(source.getStructureId()));
          for (CmsRelation relation : relationsToFile) {
              try {
                  CmsResource referencingPage = relation.getSource(m_cms, CmsResourceFilter.DEFAULT);
                  if (CmsResourceTypeXmlContainerPage.isContainerPage(referencingPage)) {
                      return referencingPage;
                  }
              } catch (CmsException e) {
                  LOG.info(e.getLocalizedMessage(), e);
              }
          }
          return null;
      }