# descendant(matchingIdentifierPath:completion:) Finds the context with the given identifier path relative to this context. ``` func descendant(matchingIdentifierPath identifierPath: [String], completion: @escaping @Sendable (CLSContext?, (any Error)?) -> Void) ``` ## Parameters `identifierPath` The identifier path of the context to find, relative to the current context. `completion` A closure the method calls with the found context, or `nil` if none could be found, and an error indicating the reason for failure, if any. ## Discussion > Important: > You can call this method from synchronous code using a completion handler, as shown on this page, or you can call it as an asynchronous method that has the following declaration: > > ```swift > func descendant(matchingIdentifierPath identifierPath: [String]) async throws -> CLSContext > ``` > > For information about concurrency and asynchronous code in Swift, see . > Important: > ClassKit calls your completion handler on an arbitrary thread. If you need to do work on a particular thread from inside the handler, dispatch that work to the appropriate queue. --- 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)