In Brendlin v. California, 551 U.S. 249 (127 SC 2400, 168 LE2d 132) (2007), the U. S. Supreme Court expressly acknowledged that "the relationship between driver and passenger is not the same in a common carrier as it is in a private vehicle, and the expectations of police officers and passengers differ accordingly." Id. at 2410 n.6. Brendlindid not purport to alter the framework in Bostick for determining whether a police officer's encounter with a bus passenger is consensual