code: func KCPTransporter(config *KCPConfig) Transporter {
  	if config == nil {
  		config = &KCPConfig{}
  		*config = DefaultKCPConfig
  	}
  	config.Init()
  
  	go snmpLogger(config.SnmpLog, config.SnmpPeriod)
  	if config.Signal {
  		go kcpSigHandler()
  	}
  
  	return &kcpTransporter{
  		config:   config,
  		sessions: make(map[string]*muxSession),
  	}
  }
docs: // KCPTransporter creates a Transporter that is used by KCP proxy client.