code: func (v *FileChooserNativeDialog) SetCancelLabel(cancel_label string) {
  	cstr := C.CString(cancel_label)
  	defer C.free(unsafe.Pointer(cstr))
  	C.gtk_file_chooser_native_set_cancel_label(v.native(), (*C.char)(cstr))
  }
docs: // SetCancelLabel is a wrapper around gtk_file_chooser_native_set_cancel_label().