Set<ImapMessage> getFlaggedMessages(ImapFlag i4flag) { if (i4flag == null || mSequence.size() == 0) return Collections.emptySet();
TreeSet<ImapMessage> getFlaggedMessages(ImapFlag i4flag) {
    Set<ImapMessage> getFlaggedMessages(ImapFlag i4flag) {        if (i4flag == null || mSequence.size() == 0)            return Collections.emptySet();        TreeSet<ImapMessage> result = new TreeSet<ImapMessage>(new ImapMessage.SequenceComparator());        for (ImapMessage i4msg : mSequence)            if (i4msg != null && i4flag.matches(i4msg))                result.add(i4msg);        return result;    }