def persist(petition_id, signer_id, theme, title, creator, end_date, name,
location, sign_date):
if not Mitzeichner.by_petition_signer(petition_id, signer_id):
mitzeichner = Mitzeichner(petition_id, signer_id, theme, title, creator, end_date, name,
location, sign_date)
db.session.add(mitzeichner)
delegations(mitzeichner)