It will have a *path operation* that will receive an `Invoice` body, and a query parameter `callback_url` that will contain the URL for the callback.

This part is pretty normal, most of the code is probably already familiar to you:

```Python hl_lines="9-13  36-53"
{!../../../docs_src/openapi_callbacks/tutorial001.py!}
```

!!! tip

		}
	}

	// the following checks are triggered if both serviceCIDR and secondaryServiceCIDR are provided
	if serviceCIDR != nil && secondaryServiceCIDR != nil {
		// should be dual stack (from different IPFamilies)
		dualstackServiceCIDR, err := netutils.IsDualStackCIDRs([]*net.IPNet{serviceCIDR, secondaryServiceCIDR})
		if err != nil {