Crash to desktop when using Custom QIODevice with QAudioSource

import sys from pathlib
import Path from PySide6.QtCore
import QIODevice from PySide6.QtMultimedia
import QAudioSource, QAudioFormat from PySide6.QtGui
import QGuiApplication from PySide6.QtQml
import QQmlApplicationEngine from PySide6.QtQuickControls2
import QQuickStyle

class AudioCaptureDevice(QIODevice):
    def __init__(self) -> None:
        super().__init__()
    def readData(self, len) -> int:
        return len
    def writeData(self, data, len) -> int: 
        print(f"Received: {len} bytes")
        return len

if __name__ == "__main__":
    app = QGuiApplication()
    QQuickStyle.setStyle("Material")
    engine = QQmlApplicationEngine()

    device = AudioCaptureDevice()
    device.open(QIODevice.WriteOnly)
    format = QAudioFormat()
    format.setSampleRate(16000)
    format.setChannelCount(1)
    format.setSampleFormat(QAudioFormat.Int16)
    audio_source = QAudioSource(format)
    audio_source.start(device)

    qml_file = Path(__file__).parent / "view.qml"
    engine.load(qml_file)
    if not engine.rootObjects():
        sys.exit(-1)
    sys.exit(app.exec())