'Map node names to events.
When a pubsub event is received for the given node,
raise the provided event.
For example::
map_node_event(\'http://jabber.org/protocol/tune\',
\'user_tune\')
will produce the events \'user_tune_publish\' and \'user_tune_retract\'
when the respective notifications are received from the node
\'http://jabber.org/protocol/tune\', among other events.
Arguments:
node       -- The node name to map to an event.
event_name -- The name of the event to raise when a
notification from the given node is received.'

def map_node_event(self, node, event_name):

    self.node_event_map[node] = event_name
