return SomeCustomClass(a_uuid=MyUuid("b8799909-f914-42de-91bc-95c819218d01"))

    client = TestClient(app)

    with client:
        response_simple = client.get("/fast_uuid")
        response_pydantic = client.get("/get_custom_class")

    assert response_simple.json() == {
        "fast_uuid": "a10ff360-3b1e-4984-a26f-d3ab460bdb51"
    }

    assert response_pydantic.json() == {