code: func FileChooserButtonNew(title string, action FileChooserAction) (*FileChooserButton, error) {
  	cstr := C.CString(title)
  	defer C.free(unsafe.Pointer(cstr))
  	c := C.gtk_file_chooser_button_new((*C.gchar)(cstr),
  		(C.GtkFileChooserAction)(action))
  	if c == nil {
  		return nil, nilPtrErr
  	}
  	obj := glib.Take(unsafe.Pointer(c))
  	return wrapFileChooserButton(obj), nil
  }
docs: // FileChooserButtonNew is a wrapper around gtk_file_chooser_button_new().