code: func (v *Pixbuf) ScaleSimple(destWidth, destHeight int, interpType InterpType) (*Pixbuf, error) {
  	c := C.gdk_pixbuf_scale_simple(v.native(), C.int(destWidth),
  		C.int(destHeight), C.GdkInterpType(interpType))
  	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
  }
docs: // ScaleSimple is a wrapper around gdk_pixbuf_scale_simple().