code: private CmsObject getRootCms() throws CmsException {
  
          if (null == m_rootCms) {
              m_rootCms = OpenCms.initCmsObject(m_cms);
              m_rootCms.getRequestContext().setSiteRoot("");
          }
          return m_rootCms;
      }
docs: Return the cms object with the site root set to "/".
  @return the cms object with the site root set to "/".
  @throws CmsException thrown if initializing the root cms object fails.