Zip列表可完成

我有一个声音类,它包含一个媒体播放器,我想写一个函数,接收声音列表并播放它们,该函数应该返回一个 完全的

interface MediaPlayer {
    fun play(): Completable
}

class Sound(val title, val mediaPlayer: MediaPlayer)

//In other class, we have a list of sound to play
val soundList = List<Sound>(mockSound1, mockSound2,..,mockSound10)

fun playSound(): Completable {
    return mockSound1.play()
}

fun playAllSounds(): Completable {
    soundList.forEach(sound -> sound.mediaPlayer.play()) //Each of this will return Completable. 

//HOW to return Completable
return ??? do we have somthing like zip(listOf<Completable>)
}


//USE
playSound().subscrible(...) //Works well

playAllSounds().subscribe()???