func (v *Pixbuf) RotateSimple(angle PixbufRotation) (*Pixbuf, error) {
	c := C.gdk_pixbuf_rotate_simple(v.native(), C.GdkPixbufRotation(angle))
	if c == nil {
		return nil, nilPtrErr
	}

	obj := &glib.Object{glib.ToGObject(unsafe.Pointer(c))}
	p := &Pixbuf{obj}
	//obj.Ref()
	runtime.SetFinalizer(p, func(_ interface{}) { obj.Unref() })
	return p, nil
}
func (v *Pixbuf) RotateSimple(angle PixbufRotation) (*Pixbuf, error) {
	c := C.gdk_pixbuf_rotate_simple(v.native(), C.GdkPixbufRotation(angle))
	if c == nil {
		return nil, nilPtrErr
	}

	obj := &glib.Object{glib.ToGObject(unsafe.Pointer(c))}
	p := &Pixbuf{obj}
	//obj.Ref()
	runtime.SetFinalizer(p, func(_ interface{}) { obj.Unref() })
	return p, nil
}
// RotateSimple is a wrapper around gdk_pixbuf_rotate_simple().