def subscribe(self, event_classes):
'''Subscribe to specific type of events
:param event_classes: list of event classes, extending one of interfaces
in the ckanext.realtime.event.base module
:type event_classes: list
'''
channels = [ec.event_name for ec in event_classes]
RedisSubscriber.subscribe(self, *channels)
log.msg('subscribed to {} new channels'.format(len(channels)))
