code: def channels(self, pattern=None):
          '''Lists the currently active channels matching ``pattern``
          '''
          if pattern:
              return self.store.execute('PUBSUB', 'CHANNELS', pattern)
          else:
              return self.store.execute('PUBSUB', 'CHANNELS'f channels(self, pattern=None):
          '''Lists the currently active channels matching ``pattern``
          '''
          if pattern:
              return self.store.execute('PUBSUB', 'CHANNELS', pattern)
          else:
              return self.store.execute('PUBSUB', 'CHANNELS')
docs: Lists the currently active channels matching ``pattern``