def METHOD_NAME(self):
    agent = self.session.query(RegistrarMain).filter_by(agent_id=agent_id).first()
    self.session.query(RegistrarMain).filter_by(agent_id=agent_id).delete()
    self.session.commit()
    agent = self.session.query(RegistrarMain).filter_by(agent_id=agent_id).first()
    self.assertIsNone(agent)