code: public CmsResource loadXmlContent(String fileName) throws CmsUgcException {
  
          checkNotFinished();
          checkEditResourceNotSet();
          if (fileName.contains("/")) {
              String message = Messages.get().container(Messages.ERR_INVALID_FILE_NAME_TO_LOAD_1, fileName).key(
                  getCmsObject().getRequestContext().getLocale());
              throw new CmsUgcException(CmsUgcConstants.ErrorCode.errMisc, message);
          }
          try {
              String contentSitePath = m_cms.getRequestContext().removeSiteRoot(
                  m_configuration.getContentParentFolder().getRootPath());
              String path = CmsStringUtil.joinPaths(contentSitePath, fileName);
              m_editResource = m_cms.readResource(path);
              CmsLock lock = m_cms.getLock(m_editResource);
              if (!lock.isOwnedBy(m_cms.getRequestContext().getCurrentUser())) {
                  m_cms.lockResourceTemporary(m_editResource);
              }
              return m_editResource;
          } catch (CmsException e) {
              throw new CmsUgcException(CmsUgcConstants.ErrorCode.errMisc, e.getLocalizedMessage());
          }
      }
docs: Loads the existing edit resource.<p>
  
  @param fileName the resource file name
  
  @return the edit resource
  
  @throws CmsUgcException if reading the resource fails