429.625.  Cost of proceeding to be paid by nonprevailing party — more than one nonprevailing party, apportionment by court. — The costs of any proceeding brought to enforce a lien filed pursuant to sections 429.600 to 429.627, including reasonable attorney's fees and prejudgment interest due to the prevailing party, shall be paid by the nonprevailing party or parties.  If more than one party is responsible for costs, fees and prejudgment interest, such costs, fees and prejudgment interest shall be equitably apportioned by the court among the responsible parties.