N.C. Gen. Stat. § 122D-15
In consideration of the acceptance of and payment for the bonds of the Authority by the holders thereof, the State does hereby pledge to and agree with the holders of any bonds of the Authority issued pursuant to the provisions of this Chapter, that the State will not impair, limit or alter the rights hereby vested in the Authority to fulfill the terms of any agreements made with the holders of the bonds of the Authority, or in any way impair the rights or remedies of such holders thereof, until such bonds, together with the interest thereon, with interest on any unpaid installments of interest, and all costs and expenses in connection with any action or proceedings by or on behalf of such holders, are fully met and discharged. The Authority is authorized to include this pledge and agreement of the State in any agreement with the holders of bonds of the Authority.
N.C. Gen. Stat. § 122D-15