code: public void setOldWebAppUrl(String webAppUrl) {
  
          if (LOG.isDebugEnabled()) {
              LOG.debug(Messages.get().getBundle().key(Messages.LOG_IMPORTEXPORT_SET_OLD_WEBAPP_URL_1, webAppUrl));
          }
          m_webAppUrl = webAppUrl;
      }
docs: Sets the URL of a 4.x OpenCms app. (e.g. http://localhost:8080/opencms/opencms/)
  from which content was exported.<p>
  
  This setting is required to import content of 4.x OpenCms apps. correct into 5.x OpenCms apps.<p>
  
  @param webAppUrl a URL of the a OpenCms app. (e.g. http://localhost:8080/opencms/opencms/)