It is the sale of a present right to create a future obligation to perform. ( Hicks v. Christeson, 174 Cal. 712, 716, 718 [ 164 P. 395]; Seeburg v. El Royale Corp., 54 Cal.App.2d 1, 4 [ 128 P.2d 362]; Brickell v. Atlas Assurance Co., Ltd., 10 Cal.App. 17, 22 [ 101 P. 16], citing Am. Eng. Ency. of Law; Cline v. Hall, 107 Okla. 218 [ 232 P. 31, 33]; Restatement of the Law of Contracts, § 47.) There is no obligation to perform until the option is exercised, and conceivably the offer may never ripen into an obligation to perform.

The defendant had the opportunity to so include such a provision, but he made only a few changes which are immaterial here and then signed the instrument, constituting an absolute acceptance thereof, and therefore a binding contract. In the case of Cline et al. v. Hall, 107 Okla. 218, 232 P. 31, plaintiffs brought action against defendant for brokers' commission for sale of stock of merchandise. In that case the contract of purchase contained a stipulation as to the amount deposited "to be . . . liquidated damages for such breach and failure."