docs: public String removeSiteRoot(String resourcename) {
  
          if (m_siteRoot == null) {
              // site root has not been set
              return resourcename;
          }
  
          String siteRoot = CmsRequestContext.getAdjustedSiteRoot(m_siteRoot, resourcename);
          if ((siteRoot.equals(m_siteRoot)) && resourcename.startsWith(siteRoot)) {
              resourcename = resourcename.substring(siteRoot.length());
          }
          return resourcename;
      }