code: func (d *DropDown) SetOptions(texts []string, selected func(text string, index int)) *DropDown {
  	d.list.Clear()
  	d.options = nil
  	for index, text := range texts {
  		func(t string, i int) {
  			d.AddOption(text, nil)
  		}(text, index)
  	}
  	d.selected = selected
  	return d
  }
docs: // SetOptions replaces all current options with the ones provided and installs
  // one callback function which is called when one of the options is selected.
  // It will be called with the option's text and its index into the options
  // slice. The "selected" parameter may be nil.