code: func (l *lifoProcessor) Push(cnx redis.Conn, src string, payload []byte) (err error) {
  	_, err = cnx.Do("RPUSH", src, payload)
  	return
  }
docs: // Push implements the `func Push` from `Processor`. It pushes the right-side
  // of the Redis structure using RPUSH, and returns any errors encountered while
  // runnning that command.