code: @Override
    public String auth(final String password) {
      checkIsInMultiOrPipeline();
      client.auth(password);
      return client.getStatusCodeReply();
    }
docs: Request for authentication in a password protected Redis server. A Redis server can be
  instructed to require a password before to allow clients to issue commands. This is done using
  the requirepass directive in the Redis configuration file. If the password given by the client
  is correct the server replies with an OK status code reply and starts accepting commands from
  the client. Otherwise an error is returned and the clients needs to try a new password. Note
  that for the high performance nature of Redis it is possible to try a lot of passwords in
  parallel in very short time, so make sure to generate a strong and very long password so that
  this attack is infeasible.
  @param password
  @return Status code reply