docs: def update_redis(project: str, environment: str, feature: str, state: str) \
          -> None:
      """
      Update redis state for a feature flag.
  
      :param project: LaunchDarkly project key.
      :param environment: LaunchDarkly environment key.
      :param feature: LaunchDarkly feature key.
      :param state: State for a feature flag.
      """
      try:
          hosts = RedisWrapper.connection_string_parser(
              os.environ.get('REDIS_HOSTS'))
      except RuntimeError as ex:
          LOG.error(ex)
          sys.exit(1)
  
      for host in hosts:
          LOG.info("connecting to %s:%s", host.host, host.port)
          try:
              if valid_state(state):
                  new_state = state.lower()
                  redis = RedisWrapper(
                      host.host,
                      host.port,
                      project,
                      environment
                  )
                  redis.update_flag_record(new_state, feature)
                  create_file(project, environment, feature, new_state)
                  LOG.info("%s was successfully updated.", feature)
              else:
                  raise Exception('Invalid state: {0}, -s needs \
                      to be either on or off.'.format(state))
          except KeyError as ex:
              LOG.error("unable to update %s. Exception: %s",
                        host.host,
                        ex)
              sys.exit(1)