Any trust agreement or agreements entered into with or for the benefit of the bondholders may prescribe by whom or on whose behalf action may be taken by the bondholders, and in the absence of any such provision in the trust agreement or agreements, any holder of a bond or bonds, or of any of the coupons of any bond or bonds, issued under the provisions of this Act, subject only to a contractual restriction binding upon any such bondholder or holders, may:
(a) By mandamus, injunction or other civil action, compel the Commission, and the member or members, officers, agents or employees thereof, to perform each and every term, provision and covenant contained in any resolution, trust agreement or contract with or for the benefit of such bondholder, and to require the carrying out of any or all such covenants and agreements of the Commission and the fulfillment of all duties imposed upon the Commission by this Act.(b) By civil action, sue to enjoin any acts or things which may be unlawful, or in violation of any of the rights of the bondholder.