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# actorSystemKey

Key which is required to be set on a `Decoder`’s `userInfo` while attempting
to `init(from:)` a `DistributedActor`. The stored value under this key must
conform to `DistributedActorSystem`.

```
static let actorSystemKey: CodingUserInfoKey
```

## Discussion

Forgetting to set this key will result in that initializer throwing, because
an actor system is required in order to call `DistributedActor/resolve(id:using:)` using it.

---

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