code: function getPluralRule() {
    if (!pluralRule) {
      var lang = navigator.language || navigator.userLanguage;
      // Convert lang to a rule index
      pluralRules.some(function(rule) {
        if (rule.locales.indexOf(lang) !== -1) {
          pluralRule = rule;
          return true;
        }
        return false;
      });
  
      // Use rule 0 by default, which is no plural forms at all
      if (!pluralRule) {
        console.error('Failed to find plural rule for ' + lang);
        pluralRule = pluralRules[0];
      }
    }
  
    return pluralRule;
  }
docs: Find the correct plural rule for the current locale
  @return a plural rule with a 'get()' function