go enum: sample

[AmitKumarDas]

// refer: https:/golang/go/issues/64739
type country struct{string} 
type Country struct{}
func(c Country) Australia() country {...} 
func(c Country) Canada() country {...}
func(c Country) China() country {...}
func(c Country) England() country {...}
func(c Country) France() country {...}
func(c Country) Germany() country {...}
func(c Country) Japan() country {...}
func(c Country) Mexico() country {...}
func(c Country) Morocco() country {...}
func(c Country) Zimbabwe() country {...}
// ...