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  "identifier" : "/documentation/AudioAccessoryKit/AudioAccessoryHeadTracking/Session/restorationID",
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  "title" : "restorationID"
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# restorationID

A stable identifier the system uses to bring this extension out of
suspension when sensor traffic arrives for this accessory.

```
final let restorationID: String?
```

## Discussion

`nil` if the host could not provide a restoration identifier for
the underlying accessory transport.

---

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