Adds multiple responses to this.
This is the same as calling [method@AlertDialog.add_response] repeatedly. The variable argument list should be `NULL`-terminated list of response IDs and labels.
Example:
```c adap_alert_dialog_add_responses (dialog, "cancel", _("_Cancel"), "discard", _("_Discard"), "save", _("_Save"), NULL); ```
| this |
an alert dialog |
| ... |
label for first response, then more id-label pairs |
| first_id |
response id |