code: public static String duration(final Number seconds, final Locale locale)
      {
          return withinLocale(new Callable<String>()
          {
              @Override
              public String call() throws Exception
              {
                  return duration(seconds);
              }
          }, locale);
      }
docs: <p>
  Same as {@link #duration(Number)} for the specified locale.
  </p>
  
  @param seconds
  Number of seconds
  @param locale
  Target locale
  @return a String with the formatted time