What is the test for obtaining a certificate of probable cause to challenge a sentence imposed through a plea bargain?

Because appellant seeks to challenge a portion of his negotiated sentence which was imposed through his plea bargain, he was required to obtain a certificate of probable cause. (See People v. Panizzon (1996) 13 Cal.4th 68, 78 [where trial court sentenced the defendant "in accordance with the previously entered plea," the defendant required a certificate of probable cause to attack his sentence on appeal].) We therefore dismiss his appeal. ( 1237.5; People v. Mendez (1999) 19 Cal.4th 1084, 1099 [explaining that the appellate court "generally may not proceed to the merits of the appeal, but must order dismissal thereof" where the defendant has not obtained a certificate of probable cause].)

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