code: func (v *FileChooser) GetCurrentFolder() (string, error) {
  	c := C.gtk_file_chooser_get_current_folder(v.native())
  	if c == nil {
  		return "", nilPtrErr
  	}
  	defer C.free(unsafe.Pointer(c))
  	return goString(c), nil
  }
docs: // GetCurrentFolder is a wrapper around gtk_file_chooser_get_current_folder().