docs: async def cleanup(self, app):
          """Close self connections."""
          self.conn.close()
          if self.pubsub_conn:
              self.pubsub_reader.cancel()
              self.pubsub_conn.close()
          # give connections a chance to actually terminate
          # TODO: use better method once it will be added,
          # see https://github.com/jonathanslenders/asyncio-redis/issues/56
          await asyncio.sleep(0)