Can a defendant who has secured the benefits of a plea agreement and knowingly waived the right to appeal?

States v. Rivera, 971 F.2d 876, 896 (2d Cir.1992). "In no circumstance ... may a defendant, who has secured the benefits of a plea agreement and knowingly and voluntarily waived the right to appeal ... then appeal the merits of a sentence conforming to the agreement," for to permit such a defendant to escape the fairly bargained-for consequences of her agreement with the government would "render the plea bargaining process and the resulting agreement meaningless." United States v. Salcido-Contreras, 990 F.2d at 53.