'Delete a a pubsub node.
Arguments:
jid      -- The JID of the pubsub service.
node     -- The node to delete.
ifrom    -- Specify the sender\'s JID.
block    -- Specify if the send call will block until a response
is received, or a timeout occurs. Defaults to True.
timeout  -- The length of time (in seconds) to wait for a response
before exiting the send call if blocking is used.
Defaults to sleekxmpp.xmlstream.RESPONSE_TIMEOUT
callback -- Optional reference to a stream handler function. Will
be executed when a reply stanza is received.'

def delete_node(self, jid, node, ifrom=None, block=True, callback=None, timeout=None):

    iq = self.xmpp.Iq(sto=jid, sfrom=ifrom, stype='set')
    iq['pubsub_owner']['delete']['node'] = node
    return iq.send(block=block, callback=callback, timeout=timeout)
