/** @since Available in iOS 8.0 and later. */
 public CFString getExtendedLanguageTag() {
   if (has(Keys.ExtendedLanguageTag())) {
     CFString val = get(Keys.ExtendedLanguageTag(), CFString.class);
     return val;
   }
   return null;
 }
 /** @since Available in iOS 8.0 and later. */
 public CMMetadataFormatDescriptionMetadataSpecification setExtendedLanguageTag(
     CFString extendedLanguageTag) {
   set(Keys.ExtendedLanguageTag(), extendedLanguageTag);
   return this;
 }