code: function (key) {
        $uses = key;
  
        // make sure to store new language key before triggering success event
        if ($storageFactory) {
          Storage.put($translate.storageKey(), $uses);
        }
  
        $rootScope.$emit('$translateChangeSuccess', {language : key});
  
        // inform default interpolator
        defaultInterpolator.setLocale($uses);
  
        var eachInterpolator = function (interpolator, id) {
          interpolatorHashMap[id].setLocale($uses);
        };
        eachInterpolator.displayName = 'eachInterpolatorLocaleSetter';
  
        // inform all others too!
        angular.forEach(interpolatorHashMap, eachInterpolator);
        $rootScope.$emit('$translateChangeEnd', {language : key});
      }
docs: @name useLanguage
  @private
  
  @description
  Makes actual use of a language by setting a given language key as used
  language and informs registered interpolators to also use the given
  key as locale.
  
  @param {string} key Locale key.