[Question] 01-defender-meta-txs relay has 4 arguments only 3 are used

In the AutoTask code the relay is defined with 4 arguments:

```js
async function relay(forwarder, request, signature, whitelist)
```

and then it is called with 3 arguments:

```js
const tx = await relay(forwarder, request, signature);
```

What sorcery is this?