code: public static ULocale acceptLanguage(String acceptLanguageList, boolean[] fallback) {
          return acceptLanguage(acceptLanguageList, ULocale.getAvailableLocales(),
                  fallback);
      }
docs: <strong>[icu]</strong> Based on a HTTP formatted list of acceptable locales, determine an available
  locale for the user.  NullPointerException is thrown if acceptLanguageList or
  availableLocales is null.  If fallback is non-null, it will contain true if a
  fallback locale (one not in the acceptLanguageList) was returned.  The value on
  entry is ignored.  ULocale will be one of the locales in availableLocales, or the
  ROOT ULocale if if a ROOT locale was used as a fallback (because nothing else in
  availableLocales matched).  No ULocale array element should be null; behavior is
  undefined if this is the case.  This function will choose a locale from the
  ULocale.getAvailableLocales() list as available.
  @param acceptLanguageList list in HTTP "Accept-Language:" format of acceptable locales
  @param fallback if non-null, a 1-element array containing a boolean to be set with
  the fallback status
  @return one of the locales from the ULocale.getAvailableLocales() list, or null if
  none match