bool QXmppRosterManager::removeItem(const QString &bareJid)
{
    QXmppRosterIq::Item item;
    item.setBareJid(bareJid);
    item.setSubscriptionType(QXmppRosterIq::Item::Remove);

    QXmppRosterIq iq;
    iq.setType(QXmppIq::Set);
    iq.addItem(item);
    return client()->sendPacket(iq);
}
bool QXmppRosterManager::renameItem(const QString &bareJid, const QString &name)
{
    if (!d->entries.contains(bareJid))
        return false;

    QXmppRosterIq::Item item = d->entries.value(bareJid);
    item.setName(name);

    QXmppRosterIq iq;
    iq.setType(QXmppIq::Set);
    iq.addItem(item);
    return client()->sendPacket(iq);
}
bool QXmppRosterManager::addItem(const QString &bareJid, const QString &name, const QSet<QString> &groups)
{
    QXmppRosterIq::Item item;
    item.setBareJid(bareJid);
    item.setName(name);
    item.setGroups(groups);
    item.setSubscriptionType(QXmppRosterIq::Item::NotSet);

    QXmppRosterIq iq;
    iq.setType(QXmppIq::Set);
    iq.addItem(item);
    return client()->sendPacket(iq);
}