def METHOD_NAME(model_instances, client):
    """ Ensure the list_budget_subfunctions endpoint returns unique values """
    response = client.post(
        "/api/v2/budget_functions/list_budget_subfunctions/", content_type="application/json", data=json.dumps({})
    )
    assert response.status_code == status.HTTP_200_OK
    assert "results" in response.json()
    assert len(response.json()["results"]) == 7