No autocomplete for flask tests

Hi!

I am currently writing tests for a flask app for the first time, and could greatly profit from autocompletion since I don't know which methods and attributes are available for a given object, however, there are no autocomplete suggestions for the flask test_client. I am using Pycharm Professional 2020.01 so there should be flask support. This is my code, if I type 'client.' I would usually expect to see suggestions, but there aren't any. Could someone give me a hint on why this could be?

import pytest
from flask import url_for
from app import app


@pytest.fixture
def client():
    app_context = app.test_request_context()
    app_context.push()
    client = app.test_client()
    return client


def test_successful_login(client):
    # Login
    response = client.post(url_for('login'), content_type='multipart/form-data', data={
        'username': 'testuser',
        'password': 'testpassword'
    })

    assert response.status_code == 302, f"Response should have been a redirect (302) but was {response.status_code}!"
    assert 'auth_tkt' in client.cookie_jar, f"No auth_tkt cookie found!"