code: function _configGetExtLang(filext) {
        var fileext1 = filext.indexOf('.') == 0 ? fileext.substring(1, filext.length) : fileext;
        if (!config.extlangs.hasOwnProperty(fileext1))
          return null;
  
        return config.extlangs[fileext1];
      }
docs: CHECK EXTLANG [