AVAudioEngine & AVAudioPlayerNode didFinish method like AVAudioPlayer

Is there any possibility to identify if the AVAudioEngine did finish its played sound? In the past I used the AVAudioPlayer's function:

func audioPlayerDidFinishPlaying(player: AVAudioPlayer, successfully flag: Bool) {
    // Code after finished the played sound
}

Now I need some effects, but there is no func of AVAudioEnginge provided that identifies the end of the played sound.

I searched a lot, but unfortunately I found only this func in the documentation of AVAudioEngine:

var running: Bool { get }

My current solution will be to check the "running" boolean, if it's false the player is not playing anymore. Does somebody know a better solution for AVAudioEngine? Thank you very much!

I attach an AVAudioPlayerNode to my engine

player = AVAudioPlayerNode()

    let file = try! AVAudioFile(forReading: url)
    let buffer = AVAudioPCMBuffer(PCMFormat: file.processingFormat, frameCapacity: AVAudioFrameCount(file.length))

    do {
        print("read")
        try file.readIntoBuffer(buffer)
    } catch _ {
    }

engine.attachNode(player)
engine.connect(player, to: engine.mainMixerNode, format: nil)

self.player.scheduleBuffer(buffer, completionHandler: {
    print("Complete")
})

        engine.prepare()
    do {
        try engine.start()
    } catch _ {
        print("Play session Error")
    }

    player.play()

I hope that helps!