Method getPreferredIDs

base/src/main/java/net/time4j/tz/Timezone.java:428–454

(
        Locale locale,
        boolean smart,
        String provider
    )

     * @see     ZoneNameProvider#getPreferredIDs(Locale, boolean)
     */
    public static Set<TZID> getPreferredIDs(
        Locale locale,
        boolean smart,
        String provider
    ) {

        ZoneModelProvider zp = getProvider(provider);

        if (zp == null) {
            return Collections.emptySet();
        }

        ZoneNameProvider np = zp.getSpecificZoneNameRepository();

        if (np == null) {
            np = NAME_PROVIDER;
        }

        Set<TZID> p = new HashSet<>();

        for (String id : np.getPreferredIDs(locale, smart)) {
            p.add(resolve(id));
        }

        return Collections.unmodifiableSet(p);

    }

    /**
     * <p>Gets the system timezone. </p>