type Provider interface {
    Links() []string
    Content(string) string
}

type RN struct {
}

func NewRN() *RN {
    return &RN{}
}

func (*RN) Links() []string {
    panic("implement me")
}

func (*RN) Content(string) string {
    panic("implement me")
}

func run(providers ...Provider) {
    for _, provider := range providers {
        for _, link := range provider.Links() {
            provider.Content(link)
        }
    }
}

func main() {
    run(NewRN(), NewRN())
}