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# init(uuid:data:)

Creates an entity identifier with the given UUID and qualifier data.

```
init(uuid: UUID, data qualifierData: Data)
```

## Parameters

`uuid`

The UUID to use for this identifier.

`qualifierData`

The data to distinguish entities that otherwise share the same UUID.

## Discussion> Warning: This initializer is annotated as returning a non-optional value but silently
> returns `nil` when `qualifierData` is not exactly eight bytes, which can surface as a
> null value in a non-optional Swift variable. Use ``doc://FSKit/documentation/FSKit/FSEntityIdentifier/init(uuid:qualifierData:)-8xlg1``
> instead, which is explicitly failable.

---

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