50a. Good faith does not suffer the same thing to be demanded twice; and in making satisfaction [for a debt or demand] it is not allowed to be done more than once. 9 Coke, 53; Dig. 50, 17, 57.50b. By good faith a possessor makes the fruits consumed his own. Tray. Max. 57.50c. Good faith demands that what is agreed upon shall be done. Dig. 19, 20, 21; Id. 19, 1, 50; Id. 50, 8, 2, 13.50e. Good faith does not allow us to demand twice the payment of the same thing. Dig. 50, 17, 57; Perline v. Dunn, 4 Johns Ch. (NY) 143.50f. A possessor in good faith is only liable for that which he himself has obtained. 2 Inst. 285.