What output will the console get in example №36

Determine what will be printed after executing the program and whether there are any errors in it.

var counter int

type Trace struct {

}

type Sender interface {
    Send(Trace)
}

func Do(sender Sender, t Trace) {
    counter++
    if counter == 100 {
        sender.Send(t)
        counter = 0        
    }
}