code: def _auth_stage1(self):
          
          iq=Iq(stanza_type="get")
          q=iq.new_query("jabber:iq:auth")
          q.newTextChild(None,"username",to_utf8(self.my_jid.node))
          q.newTextChild(None,"resource",to_utf8(self.my_jid.resource))
          self.send(iq)
          self.set_response_handlers(iq,self.auth_stage2,self.auth_error,
                              self.auth_timeout,timeout=60)
          iq.free()
docs: Do the first stage (<iq type='get'/>) of legacy ("plain" or
          "digest") authentication.
  
          [client only]