'Called on the client side to cancel a request for data readout.
Composes a message with the cancellation and sends it to the device(s).
Does not block, the callback will be called when cancellation is
confirmed.
Arguments:
session        -- The session id of the request to cancel'

def cancel_request(self, session):

    seqnr = session
    iq = self.xmpp.Iq()
    iq['from'] = self.sessions[seqnr]['from']
    iq['to'] = self.sessions[seqnr]['to']
    iq['type'] = 'get'
    iq['id'] = seqnr
    iq['cancel']['seqnr'] = seqnr
    iq.send(block=False)
