def main(request, order_by=None, override=None):
    if request.user.is_authenticated():
        subs = SubscribedUser.objects.filter(user = request.user).select_related(depth = 1)
        topics = [sub.topic for sub in subs]
        if topics:
            links = Link.objects.get_query_set_with_user(request.user).filter(topic__in = topics).select_related()
        else:
            links = Link.objects.get_query_set_with_user(request.user).select_related()
        if override == 'all':
            links = Link.objects.get_query_set_with_user(request.user).select_related()
    else:
        links = Link.objects.all().select_related()

    if order_by == 'new':
        links = links.order_by('-created_on')

    if override == 'all':
        page = 'all'
    elif order_by == 'new':
        page = 'new'
    else:
        page = 'hot'

    links, page_data = get_paged_objects(links, request, defaults.LINKS_PER_PAGE)
    tags = Tag.objects.filter(topic__isnull=True).select_related().order_by('-updated_on')[:defaults.TAGS_ON_MAINPAGE]
    if request.user.is_authenticated():
        subscriptions = SubscribedUser.objects.filter(user=request.user).select_related()
    else:
        subscriptions = SubscribedUser.objects.get_empty_query_set()
    top_topics = Topic.objects.all().order_by('-num_links')[:defaults.TOP_TOPICS_ON_MAINPAGE]
    new_topics = Topic.objects.all().order_by('-updated_on')[:defaults.NEW_TOPICS_ON_MAINPAGE]
    payload = {'links': links, 'tags': tags, 'subscriptions': subscriptions, 'top_topics': top_topics, 'new_topics': new_topics, 'page_data': page_data, 'page': page}
    return render(request, payload, 'news/main.html')
Given a TVTK dataset `dataset` return the string dataset type of
dataset/ETHPy150Open agiliq/django-socialnews/socialnews/news/topics.py/main--crossover with--dataset/ETHPy150Open enthought/mayavi/mayavi/core/pipeline_info.py/get_tvtk_dataset_name