func (v *Surface) destroy() {
	if v.surface != nil {
		C.cairo_surface_destroy(v.native())
		v.surface = nil
	}
}
func (v *Surface) destroy() {
	if v.surface != nil {
		C.cairo_surface_destroy(v.native())
		v.surface = nil
	}
}
// destroy is a wrapper around cairo_surface_destroy().