# withMagicCookie(_:) Returns the magic cookie. ``` func withMagicCookie(_ body: (UnsafeRawBufferPointer?) throws -> R) rethrows -> R ``` ## Parameters `body` A pointer to the magic cookie in the audio format description. --- 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)