Google Cloud Functions CORS Request (Python)

from flask import jsonifydef test_cors_json(request):    if request.method == 'OPTIONS':        headers = {            # 'Access-Control-Allow-Origin': 'https://mydomain.com',            'Access-Control-Allow-Origin': '*',            'Access-Control-Allow-Methods': 'GET, POST, OPTIONS',            'Access-Control-Allow-Headers': 'Content-Type, Authorization',            'Access-Control-Max-Age': '3600'            # 'Access-Control-Allow-Credentials': 'true'        }        return ('', 204, headers)    '''    headers = {        'Access-Control-Allow-Origin': 'https://mydomain.com',        'Access-Control-Allow-Credentials': 'true'    }    return ('Hello World!', 200, headers)    '''    data = {        'name': 'Test CORS OK'    }    response = jsonify({        'data': data    })    response.headers.set('Access-Control-Allow-Origin', '*')    return response