# XCTKeyPathExpectation.SynchronousFilter ``` typealias SynchronousFilter = @Sendable (T, NSKeyValueObservedChange) -> Bool ``` --- 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)