code: func (v *Entry) GetIconTooltipText(iconPos EntryIconPosition) (string, error) {
  	c := C.gtk_entry_get_icon_tooltip_text(v.native(),
  		C.GtkEntryIconPosition(iconPos))
  	if c == nil {
  		return "", nilPtrErr
  	}
  	return goString(c), nil
  }
docs: // GetIconTooltipText() is a wrapper around gtk_entry_get_icon_tooltip_text().