29.A similar solution, and under the same name, was also used in Switzerland. Even though there is no specific provision dealing with rebus sic stantibus, the Code of Obligations, in its art. 373 allows contractors to raise their price "where extraordinary circumstances which could not be foreseen, or which were excluded by the basis upon which both parties entered into the contract, prevent or unduly impede the completion, the court may, at its discretion, increase the price or rescind the contract." After World War I, Swiss courts started applying this article analogically, which had the effect of implementing rebus sic stantibus as a general rule in Swiss law.