Pinger.TimeOut cause nil pointer error

[gaorongfu]

code :

pinger, err := probing.NewPinger(ip)
if err != nil {
fmt.Printf("%s : %s", allIp[idx], err.Error())
return
}
pinger.SetPrivileged(true)
pinger.Timeout = time.Second
pinger.Count = 3

            err := pinger.Run() // Blocks until finished.
		if err != nil {
			panic(err)
		}

error:

panic: runtime error: invalid memory address or nil pointer dereference
[signal 0xc0000005 code=0x0 addr=0xf0 pc=0xbb5fff]

goroutine 1 [running]:
github.com/prometheus-community/pro-bing.(*Pinger).RunWithContext(0xc5d220?, {0xc5e250?, 0xdbf6e0?})
E:/goProjects/pkg/mod/github.com/prometheus-community/[email protected]/ping.go:520 +0x3f
github.com/prometheus-community/pro-bing.(*Pinger).Run(...)
E:/goProjects/pkg/mod/github.com/prometheus-community/[email protected]/ping.go:511
main.main()
E:/goProjects/src/fping/main.go:44 +0x3d6