def event_callback(event: Event):
    pass  # pragma: nocover


subrouter = APIRouter()


@subrouter.post("/invoices/", callbacks=invoices_callback_router.routes)
def create_invoice(invoice: Invoice, callback_url: Optional[HttpUrl] = None):
    """
    Create an invoice.

    This will (let's imagine) let the API user (some external developer) create an
    invoice.