Remedies.

Any holder of bonds issued under the provisions of this law or any of the coupons appertaining thereto, and the trustee under any trust agreement, except to the extent the rights herein given may be restricted by such trust agreement or the resolution authorizing the issuance of such bonds, may, either at law or in equity, by suit, action, mandamus or other proceedings, protect and enforce any and all rights under the laws of the state or granted hereunder or under such trust agreement or resolution, and may enforce and compel the performance of all duties required by this law or by such trust agreement or resolution to be performed by the unit or by any officer thereof, including the fixing, charging and collecting of rates, rentals and other charges.