2-4-501. Declaratory rulings by agencies. Each agency shall provide by rule for the filing and prompt disposition of petitions for declaratory rulings as to the applicability of any statutory provision or of any rule or order of the agency. A copy of a declaratory ruling must be filed with the secretary of state for publication in the register. A declaratory ruling or the refusal to issue such a ruling shall be subject to judicial review in the same manner as decisions or orders in contested cases.