In any action in which a party alleges that an act, policy or practice of a public body, as defined in ORS 174.109, or of any officer, employee or agent of a public body, as defined in ORS 174.109, is unconstitutional or is otherwise contrary to law, the party may continue to prosecute the action and the court may issue a judgment on the validity of the challenged act, policy or practice even though the specific act, policy or practice giving rise to the action no longer has a practical effect on the party if the court determines that:
ORS 14.175