code: public static String naturalTime(final Date reference, final Date duration, final Locale locale)
      {
          return withinLocale(new Callable<String>()
          {
              public String call()
              {
                  return naturalTime(reference, duration);
              }
          }, locale);
      }
docs: <p>
  Same as {@link #naturalTime(Date, Date) naturalTime} for the specified
  locale.
  </p>
  
  @param reference
  Date to be used as reference
  @param duration
  Date to be used as duration from reference
  @param locale
  Target locale
  @return String representing the relative date