docs: public String getRfsPrefix(String vfsName) {
  
          if (vfsName != null) {
              Iterator<CmsStaticExportRfsRule> it = m_rfsRules.iterator();
              while (it.hasNext()) {
                  CmsStaticExportRfsRule rule = it.next();
                  if (rule.getSource().matcher(vfsName).matches()) {
                      return rule.getRfsPrefix();
                  }
              }
          }
          return m_rfsPrefix;
      }