XmppHeaderMapper.AbstractXmppConnectionAwareEndpoint.Messages when a
particular Presence event occurs within the logged-in user's Roster.ExtensionElementProvider to build an ExtensionElement
for the Stanza.addExtension(ExtensionElement)
instead of body.payload against an incoming
Message.StanzaFilter to use for the incoming packets.XMPPTCPConnection object.HeaderMapper
but parameterized with the Smack API Message.Message objects
that handle XMPP events.