No 'do' method? about rxgo HOT 3 CLOSED

// wrap a side effect in an EventHandler
handler := handlers.NextFunc(func(v interface{}) {
        fmt.Println(v)
})
sc := observable.Just(1).Subscribe(handler)
<-sc

// or ...

// wrap the side effect in a MappableFunc and throw away the returned Observable
_ = observable.Just(1).Map(func(v interface{}) interface{} {
        fmt.Print(v)
        return nil
})

printFunc := func(item interface{}) {
        fmt.Print(item)
}
c := connectable.Just(1).Subscribe(handlers.NextFunc(printFunc))
results := c.Connect()
<-results

// can be
results = connectable.Just(1).Do(printFunc).Connect()
<-results