code: func NewServer() *Server {
  	if f := flag.Lookup("toolbox.trace"); f != nil {
  		Trace, _ = strconv.ParseBool(f.Value.String())
  	}
  
  	s := &Server{
  		sessions: make(map[uint64]*session),
  		schemes:  make(map[string]FileHandler),
  		chmod:    os.Chmod,
  		chown:    os.Chown,
  	}
  
  	s.handlers = map[int32]func(*Packet) (interface{}, error){
  		OpCreateSessionV4:  s.CreateSessionV4,
  		OpDestroySessionV4: s.DestroySessionV4,
  		OpGetattrV2:        s.GetattrV2,
  		OpSetattrV2:        s.SetattrV2,
  		OpOpen:             s.Open,
  		OpClose:            s.Close,
  		OpOpenV3:           s.OpenV3,
  		OpReadV3:           s.ReadV3,
  		OpWriteV3:          s.WriteV3,
  	}
  
  	for op := range s.handlers {
  		s.Capabilities = append(s.Capabilities, Capability{Op: op, Flags: 0x1})
  	}
  
  	return s
  }
docs: // NewServer creates a new Server instance with the default handlers