code: def collect(self):
          
          if redis is None:
              self.log.error('Unable to import module redis')
              return {}
  
          for nick in self.instances.keys():
              (host, port, unix_socket, auth) = self.instances[nick]
              self.collect_instance(nick, host, int(port), unix_socket, auth)
docs: Collect the stats from the redis instance and publish them.