如何用AVAudioEngine同时改变音高和音速

import AVFoundation

func changePitchAndSpeed(url: URL, pitch: Float, speed: Float) {
    let audioEngine = AVAudioEngine()
    let audioPlayerNode = AVAudioPlayerNode()
    let audioFile = try! AVAudioFile(forReading: url)
    
    audioEngine.attach(audioPlayerNode)
    
    let pitchEffect = AVAudioUnitTimePitch()
    pitchEffect.pitch = pitch
    
    let speedEffect = AVAudioUnitVarispeed()
    speedEffect.rate = speed
    
    audioEngine.attach(pitchEffect)
    audioEngine.attach(speedEffect)
    
    audioEngine.connect(audioPlayerNode, to: pitchEffect, format: audioFile.processingFormat)
    audioEngine.connect(pitchEffect, to: speedEffect, format: audioFile.processingFormat)
    audioEngine.connect(speedEffect, to: audioEngine.mainMixerNode, format: audioFile.processingFormat)
    
    audioPlayerNode.scheduleFile(audioFile, at: nil)
    
    do {
        try audioEngine.start()
    } catch {
        print("Failed to start audio engine: \(error.localizedDescription)")
        return
    }
    
    audioPlayerNode.play()
}

let audioURL = Bundle.main.url(forResource: "example", withExtension: "mp3")!
changePitchAndSpeed(url: audioURL, pitch: 1.5, speed: 1.2)