                     context("when is not likely to keep up") {
                         it("changes state to buffering") {
                             let playback = AVFoundationPlayback()
+                            playback.player = AVPlayerStub()
 
                             playback.play()
                             playback.pause()

                    context("when play is called") {
                        it("changes current state to playing") {
                            let playback = AVFoundationPlayback()

                            playback.play()

                            expect(playback.isPlaying).to(beTrue())
                            expect(playback.currentState).to(equal(.playing))
                        }
                    }

                    context("when pause is called") {
                        it("changes current state to paused") {
                            let playback = AVFoundationPlayback()

                            playback.pause()

                    context("when stop is called") {
                        it("changes state to idle") {
                            let playback = AVFoundationPlayback()

                            playback.play()
                            playback.pause()
                            playback.stop()
