code: async def _connect_sentinel(self, address, timeout, pools):
          
          try:
              with async_timeout(timeout, loop=self._loop):
                  pool = await create_pool(
                      address, minsize=1, maxsize=2,
                      parser=self._parser_class,
                      loop=self._loop)
              pools.append(pool)
              return pool
          except asyncio.TimeoutError as err:
              sentinel_logger.debug(
                  "Failed to connect to Sentinel(%r) within %ss timeout",
                  address, timeout)
              return err
          except Exception as err:
              sentinel_logger.debug(
                  "Error connecting to Sentinel(%r): %r", address, err)
              return err
docs: Try to connect to specified Sentinel returning either
          connections pool or exception.