Python Firestore Asyncio

Ubuntu 20.04.1 LTS

Python 3.8.6 

firebase-admin==4.4.0
google-cloud-core==1.4.3
google-cloud-firestore==2.0.1
grpcio==1.33.2

import asyncioimport sysimport firebase_adminfrom firebase_admin import credentials, firestore, authfrom firebase_admin.firestore import AsyncDocumentReference# from firebase_admin.firestore import AsyncClientasync def main():    cred = credentials.Certificate('firebase-adminsdk.json')    app = firebase_admin.initialize_app(cred)    # db = firestore.client(app = app)    db = firestore.AsyncClient(credentials=app.credential.get_credential(), project=app.project_id)    user_ref = db.collection('user')    ref = user_ref.document()    await ref.set({'name': 'test-user'})    docs = await user_ref.get()    for doc in docs:        print(doc.id, doc.get('name'))    docs = user_ref.stream()    async for doc in docs:        print(doc.id, doc.get('name'))    print('END')if __name__ == "__main__":    asyncio.run(main())    print('main-END')