'Raise events for node subscription notifications.'

def _handle_event_subscription(self, msg):

    node = msg['pubsub_event']['subscription']['node']
    event_name = self.node_event_map.get(node, None)
    self.xmpp.event('pubsub_subscription', msg)
    if event_name:
        self.xmpp.event(('%s_subscription' % event_name), msg)
