code: public PrettyTime setLocale(Locale locale)
     {
        if (locale == null)
           locale = Locale.getDefault();
  
        this.locale = locale;
        for (TimeUnit unit : units.keySet()) {
           if (unit instanceof LocaleAware)
              ((LocaleAware<?>) unit).setLocale(locale);
        }
        for (TimeFormat format : units.values()) {
           if (format instanceof LocaleAware)
              ((LocaleAware<?>) format).setLocale(locale);
        }
        return this;
     }
docs: Set the the {@link Locale} for this {@link PrettyTime} object. This may be an expensive operation, since this
  operation calls {@link TimeUnit#setLocale(Locale)} for each {@link TimeUnit} in {@link #getUnits()}.