docs: protected String getResourceName() {
  
          String resource = getItem().get(m_resColumnPathId).toString();
          if (!getWp().getCms().existsResource(resource, CmsResourceFilter.DEFAULT)) {
              String siteRoot = OpenCms.getSiteManager().getSiteRoot(resource);
              if (CmsStringUtil.isNotEmptyOrWhitespaceOnly(siteRoot)) {
                  resource = resource.substring(siteRoot.length());
              }
              if (!getWp().getCms().existsResource(resource, CmsResourceFilter.DEFAULT)) {
                  resource = null;
              }
          }
          return resource;
      }