def METHOD_NAME(self, *args, **kwargs):
    qs = (
        Membership.objects.filter(
            elected=True, ballot__election__slug="parl.2019-12-12"
        )
        .select_related(
            "ballot", "ballot__election", "ballot__post", "person", "party"
        )
        .prefetch_related("person__tmp_person_identifiers")
    )
    response = HttpResponse(content_type="text/html")
    response[
        "Content-Disposition"
    ] = 'attachment; filename="parl-2019-12-12_winners.csv"'
    fieldnames = [
        "election_slug",
        "ballot_paper_id",
        "gss",
        "person_id",
        "person_name",
        "party_id",
        "party_name",
        "theyworkforyou_url",
        "wikidata_id",
        "updated",
        "previous_winner",
        "previous_winner_party",
    ]
    writer = csv.DictWriter(response, fieldnames=fieldnames)
    writer.writeheader()
    for membership in qs:
        twfy_id = membership.person.get_single_identifier_of_type(
            "theyworkforyou"
        )
        theyworkforyou_url = None
        if twfy_id:
            theyworkforyou_url = (
                "http://www.theyworkforyou.com/mp/{}".format(
                    twfy_id.internal_identifier
                )
            )
        result = ResultEvent.objects.filter(
            election=membership.ballot.election,
            post=membership.ballot.post,
            winner=membership.person,
        )
        created = result.first().created if result.exists() else None
        previous_ballot = Ballot.objects.get_previous_ballot_for_post(
            membership.ballot
        )
        previous_winner_qs = previous_ballot.membership_set.filter(
            elected=True
        )
        if previous_winner_qs.exists():
            previous_winner = previous_winner_qs.first()
        else:
            previous_winner = None
        gss = None
        if membership.ballot.post.identifier.startswith("gss:"):
            gss = membership.ballot.post.identifier[4:]
        out = {
            "election_slug": membership.ballot.election.slug,
            "ballot_paper_id": membership.ballot.ballot_paper_id,
            "gss": gss,
            "person_id": membership.person_id,
            "person_name": membership.person.name,
            "party_id": membership.party.ec_id,
            "party_name": membership.party.name,
            "theyworkforyou_url": theyworkforyou_url,
            "wikidata_id": membership.person.get_single_identifier_of_type(
                "wikidata_id"
            ).value,
            "updated": created,
        }
        if previous_winner:
            out.update(
                {
                    "previous_winner": previous_winner.person_id,
                    "previous_winner_party": previous_winner.party.ec_id,
                }
            )
        writer.writerow(out)
    return response