Art. 1271.  Forced alienation of immovables subject to collation.

But if the donee has been forced to alienate the immovable property, he shall be obliged to collate by taking less the price he has received from this sale and no more.

As, for example, if the donee shall be obliged to submit to a sale of the immovable for some object of public utility, or to discharge a mortgage imposed by the donor, or because the immovable was held in common with another person who has prayed for the sale in order to obtain a partition of it.