gtk/tooltip.go
func (t *Tooltip) SetIconFromIconName(iconName string, size IconSize) {
	cstr := C.CString(iconName)
	defer C.free(unsafe.Pointer(cstr))
	C.gtk_tooltip_set_icon_from_icon_name(t.native(),
		(*C.gchar)(cstr),
		C.GtkIconSize(size))
}
func (t *Tooltip) SetIconFromIconName(iconName string, size IconSize) {
	cstr := C.CString(iconName)
	defer C.free(unsafe.Pointer(cstr))
	C.gtk_tooltip_set_icon_from_icon_name(t.native(),
		(*C.gchar)(cstr),
		C.GtkIconSize(size))
}
// SetIconFromIconName is a wrapper around gtk_tooltip_set_icon_from_icon_name().