code: func ScaleNew(orientation Orientation, adjustment *Adjustment) (*Scale, error) {
  	c := C.gtk_scale_new(C.GtkOrientation(orientation), adjustment.native())
  	if c == nil {
  		return nil, nilPtrErr
  	}
  	return wrapScale(glib.Take(unsafe.Pointer(c))), nil
  }
docs: // ScaleNew is a wrapper around gtk_scale_new().