Import "golang.org/x/net/icmp" failed! , go语

Import "golang.org/x/net/icmp" failed!

I'm new to Golang and I cant find any good resource about this subject

I see that people use import "golang.org/x/net/icmp" or things like this(https://github.com/tatsushid/go-fastping/blob/master/fastping.go),but I cant get them work ! 
I tried to install the package but get error like

go get golang.org/x/net 
package golang.org/x/net: unrecognized import path "golang.org/x/net"

or
go get github.com/golang/net

but all the import are pointing to golang.org/x/net/...

I don't know how should I use packages golang.org/x/net/icmp  and other related ones...

解决方法：

（编辑：李大同）

【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容!