def count_unread(self):
        if self.track_unread:
            return self.feed_markers.count('unread')
An observer which updates the proxy when the data changes.
dataset/ETHPy150Open tschellenbach/Stream-Framework/stream_framework/feeds/notification_feed/base.py/BaseNotificationFeed.count_unread--crossover with--dataset/ETHPy150Open ContinuumIO/ashiba/enaml/enaml/widgets/bounded_datetime.py/BoundedDatetime._update_proxy