The State of Nebraska does hereby pledge to and agree with the holders of any bonds and with those persons who may enter into contracts with any joint public agency under the Joint Public Agency Act that the state will not alter, impair, or limit the rights thereby vested until the bonds, together with applicable interest, are fully met and discharged and such contracts are fully performed. Nothing contained in the Joint Public Agency Act shall preclude such alteration, impairment, or limitation if and when adequate provisions are made by law for the protection of the holders of the bonds or persons entering into contracts with any joint public agency. Each joint public agency may include this pledge and undertaking for the state in such bonds or contracts.