(a) The parties in a contested case may, by a stipulation in writing filed with the administrative law judge, agree upon any fact involved in the controversy, which stipulation shall be used as evidence at the hearing and be binding on the parties thereto. Parties should agree upon facts when practicable.
(b) Except as otherwise provided by law, disposition may be made of a contested case by stipulation, agreed settlement, consent order, waiver, default, or other method agreed upon by the parties.