by the court; the test is whether on account of an act of the party persuading the court to pass an order held at the end as not sustainable, has resulted in one party gaining an advantage which it would not have otherwise earned. 13. In the matter of Binayak Swain (supra), this Court held that the obligation for restitution arises automatically on the reversal or modification of the decree and necessarily carries with it the right to restitution of all that has been done under the erroneous decree; and the Court in making restitution is bound to restore the parties, so far as they can be restored to the same position they were in at the time when the Court by its erroneous action had displaced them from. 14. Drawing the distinction between a decree holder who himself is the auction purchaser and a third-party auction purchaser, this Court in Binayak Swain (supra) approved an earlier judgment of Privy Council in the matter of Zain-Ul- Abdin Khan vs. Muhammad Asghar Ali Khan10 to