# fitted(to:validateOn:eventHandler:) Fits a transformer to a sequence of examples while validating with a validation sequence. ``` func fitted(to input: InputSequence, validateOn validation: Validation, eventHandler: EventHandler? = nil) async throws -> SupervisedEstimatorToTemporalAdaptor.Transformer where InputSequence : Sequence, Validation : Sequence, FeatureSequence : TemporalSequence, InputSequence.Element == AnnotatedFeature, Validation.Element == AnnotatedFeature, FeatureSequence.Feature == Base.Transformer.Input ``` ## Parameters `input` A sequence of examples used for fitting the transformer. `validation` A sequence of examples used for validating the fitted transformer. `eventHandler` An event handler. ## Return Value The fitted transformer. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)