code: func OnGeneralEvent(ctx context.Context, sctx *variable.SessionVars, event plugin.GeneralEvent, cmd string) {
  	fmt.Println("conn_ip_example notifiy called")
  	fmt.Println("variable test: ", variable.GetSysVar("conn_ip_example_test_variable").Value)
  	fmt.Printf("new connection by %s\n", ctx.Value("ip"))
  	return
  }
docs: // OnGeneralEvent implements TiDB Audit plugin's OnGeneralEvent SPI.