code: func (c *Cmd) ExpectSlice(resp ...interface{}) *Cmd {
  	response := []interface{}{}
  	for _, r := range resp {
  		response = append(response, r)
  	}
  	c.Responses = append(c.Responses, Response{response, nil})
  	return c
  }
docs: // ExpectSlice makes it easier to expect slice value
  // e.g - HMGET command