code: func (c *asyncClient) Dbsize() (result FutureInt64, err Error) {
  	var resp *PendingResponse
  	resp, err = c.conn.QueueRequest(&DBSIZE, [][]byte{})
  	if err == nil {
  		result = resp.future.(FutureInt64)
  	}
  	return result, err
  
  }
docs: // Redis DBSIZE command.