code: func (v *Image) SetFromStock(stock Stock, size IconSize) {
  	cstr := C.CString(string(stock))
  	defer C.free(unsafe.Pointer(cstr))
  	C.gtk_image_set_from_stock(v.native(), (*C.gchar)(cstr),
  		C.GtkIconSize(size))
  }
docs: // SetFromStock is a wrapper around gtk_image_set_from_stock().