(a) All bond issues for which the commission is serving as fiscal agent shall be considered to have been canceled and paid in advance of their due date or date of redemption if there shall have been deposited with the commission either:
(1) Moneys sufficient to pay when and as due at maturity or prior redemption all amounts of principal, redemption premium, if any, and interest payable on such bonds; or
(2) Securities of a quality in which the commission is authorized by law to invest moneys under its control, the principal of and interest on which will provide moneys sufficient to pay when and as due at maturity or prior redemption all amounts of principal, redemption premium, if any, and interest payable on such bonds.
(b) The moneys and securities held by the commission pursuant to this section shall be held by the commission in trust and irrevocably dedicated solely to the payment of principal or redemption price, if applicable, of and interest on the bonds: Provided, That this action shall be taken solely at the direction of the issuer. Following such irrevocable commitment of moneys and securities in trust, funds on account with the commission for said bonds which are surplus may be immediately returned to the issuer.