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# knownClassifications(forRevision:)

Requests the collection of classifications that the Vision framework recognizes.

```
class func knownClassifications(forRevision requestRevision: Int) throws -> [VNClassificationObservation]
```

## Parameters

`requestRevision`

The revision of the request for which to report classifications.

## Return Value

An array of classifications for the revision, or `nil` if an error occurs.

## Discussion

---

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