# restoreTrainingSession(sessionParameters:) Creates an asynchronous training session for an object detector by restoring an existing training session’s state from its parameters. ``` static func restoreTrainingSession(sessionParameters: MLTrainingSessionParameters) throws -> MLTrainingSession ``` ## Parameters `sessionParameters` The [`MLTrainingSessionParameters`](/documentation/CreateML/MLTrainingSessionParameters) instance you used to create the training session with [`makeTrainingSession(trainingData:annotationType:parameters:sessionParameters:)`](/documentation/CreateML/MLObjectDetector/makeTrainingSession(trainingData:annotationType:parameters:sessionParameters:)). ## Return Value An [`MLTrainingSession`](/documentation/CreateML/MLTrainingSession) that represents the object-detector training session. ## Discussion Use [`resume(_:)`](/documentation/CreateML/MLObjectDetector/resume(_:)) to start the [`MLTrainingSession`](/documentation/CreateML/MLTrainingSession) instance you get from this method. --- 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)