In Cruz v. State, 530 S.W.2d 817 (Tex. Cr. App. 1975), the defendant said that his plea of guilty in a prosecution for murder was involuntary because the trial court did not follow the State's recommendation of probation. The Court said: Appellant in effect urges a rule of law wherein a defendant as a matter of right may withdraw a plea of guilty when the trial court refuses to follow a punishment recommendation of the prosecutor that is the result of a negotiated plea agreement. The Court recognized that negotiated pleas are an integral and essential part of our system of criminal justice. In cases where the guilty plea is the result of a negotiated plea agreement, the trial court in exercising its authority to assess punishment also serves as a check upon oppressive or unfair bargains or those not in the public interest.