How to write a unit test for flask based Azure Function App

Question

I am using Flask with Azure Functions as described by Microsoft, e.g. here: https://github.com/Azure-Samples/flask-app-on-azure-functions/ So the code in the Azure function file __ init__.py follows this concept:

import azure.functions as func
from api.app import application

def main(req: func.HttpRequest, context: func.Context) -> func.HttpResponse:
    """Each request is redirected to the WSGI handler.
    """
    return func.WsgiMiddleware(application).handle(req, context)

and then the main code follows in app.py

from resources.users import Users

application = Flask(__name__)
api = Api(application)

# API routes
api.add_resource(Users, '/api/users')

Example unit test

class TestRoute(unittest.TestCase):

    def test_users(self):

        req = func.HttpRequest(
            method='GET',
            body=None,
            url='/users'

        resp = main(req)
        self.assertEqual(resp.status_code, 200)

When I try to run the test, I am missing the context object in the __ init__.py. So somehow I need to mock this context object, but I don't know how to do this. Any hints? When printing this object it says: <azure_functions_worker.bindings.context.Context object at 0x7f4bb88504c0>