In Ablett v. Clauson (1954) 43 Cal.2d 280, the court explained: "The general rule regarding contracts to agree in the future is stated to be as follows: 'although a promise may be sufficiently definite when it contains an option given to the promisor or promisee, yet if an essential element is reserved for the future agreement of both parties, the promise can give rise to no legal obligation until such future agreement. Since either party by the terms of the promise may refuse to agree to anything to which the other party will agree, it is impossible for the law to affix any obligation to such a promise.' " ( Id. at pp. 284-285.)