query jabber:iq:roster org.jivesoftware.smack.roster.provider.RosterPacketProvider sub urn:xmpp:features:pre-approval org.jivesoftware.smack.roster.provider.SubscriptionPreApprovalStreamFeatureProvider ver urn:xmpp:features:rosterver org.jivesoftware.smack.roster.provider.RosterVerStreamFeatureProvider