How to use the cldr.extractMonthNames function in cldr

function _extractLocaleMonths(abbr, locale) {
      var months = []
      if(abbr) {
        months = cldr ? cldr.extractMonthNames(locale).format.abbreviated : ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'];
      }
      else {
        months = cldr ? cldr.extractMonthNames(locale).format.wide : ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'];
      }

      months.unshift('');
      return months;
    };