code: func (v *FileChooser) AddShortcutFolder(folder string) bool {
  	cstr := C.CString(folder)
  	defer C.free(unsafe.Pointer(cstr))
  	c := C.gtk_file_chooser_add_shortcut_folder(v.native(), cstr, nil)
  	return gobool(c)
  }
docs: // AddShortcutFolder is a wrapper around gtk_file_chooser_add_shortcut_folder().