In In the Interest of J. N. T., 212 Ga. App. 498, 500 (441 S.E.2d 918) (1994) the Court held, with reference to O.C.G.A. 19-9-6 (3), that "joint physical custody" is divided physical custody between estranged parents and that the Code section "contemplates no other purpose sufficient to authorize . . . a true joint physical custody arrangement." See also In the Interest of A. R. B., 209 Ga. App. 324, 326 (2) (433 S.E.2d 411) (1993) (physical precedent only). This is a perfectly rational statutory scheme, considering the fact that, traditionally, the constitutional rights of a parent could not be interfered with by the State or a third party, absent a showing of unfitness of such parent. It would generally make no sense to award joint custody to an unfit parent. Georgia law does not, however, preclude an award of joint custody to a third party by the trial court upon the consent of the parent to such an arrangement or upon a waiver by such parent of constitutionally protected parental rights, provided that the trial court determines that the award is in the best interest of the child. Rights and obligations which the court has no authority to create may become enforceable by order of the court where the parties agree to such an arrangement, and the court approves the agreement and incorporates it into the order of the court. An agreement to pay college expenses or to provide support after a child attains the age of majority are examples of such arrangements.