code: func (n *Node) doRaftShrinkLog(conn redcon.Conn, cmd redcon.Command) (interface{}, error) {
  	if len(cmd.Args) != 1 {
  		return nil, ErrWrongNumberOfArguments
  	}
  	if s, ok := n.store.(shrinkable); ok {
  		err := s.Shrink()
  		if err != nil {
  			conn.WriteError("ERR " + err.Error())
  			return nil, nil
  		}
  		conn.WriteString("OK")
  		return nil, nil
  	}
  	conn.WriteError("ERR log is not shrinkable")
  	return nil, nil
  }
docs: // doRaftShrinkLog handles a "RAFTSHRINKLOG" client command.