 }
 
 #elseif os(macOS) // macOS support using CVDisplayLink --------------------------------------------------
+
+import CoreVideo
 
 extension DisplayLink {
     

    }
}

#endif // ------------------------------------------------------------------------------------------

            /// Called for each frame from the CADisplayLink.
            @objc dynamic func frame(_ displayLink: CADisplayLink) {

                let frame = Frame(
                    previousTimestamp: displayLink.timestamp,
                    timestamp: displayLink.targetTimestamp)

                callback?(frame)
            }
