environment/lib/python2.7/site-packages/IPython/utils/notification.py
def _observers_for_notification(self, ntype, sender):
        """Find all registered observers that should recieve notification"""

        keys = (
                   (ntype,sender),
                   (ntype, None),
                   (None, sender),
                   (None,None)
               )

        obs = set()
        for k in keys:
            obs.update(self.observers.get(k, set()))

        return obs
def _observers_for_notification(self, ntype, sender):
        """Find all registered observers that should recieve notification"""

        keys = (
                   (ntype,sender),
                   (ntype, None),
                   (None, sender),
                   (None,None)
               )

        obs = set()
        for k in keys:
            obs.update(self.observers.get(k, set()))

        return obs
Find all registered observers that should recieve notification