this court’s direction after the Supreme Court remanded his case, Johnson contends that his sentence violated the Sixth Amendment and that the district court’s comments at the sentencing hearing disclose that it would have imposed a lower sentence under an advisory guidelines scheme. The government maintains that Johnson’s career offender sentence did not violate the Sixth Amendment, but concedes that the record indicates the district court might have imposed a lower sentence had it had discretion to do so. Johnson contends that, under Booker, the district court violated his Sixth Amendment rights by making impermissible factual findings to classify him as a career offender. We are satisfied that his claim is foreclosed by United States v. Collins, 412 F.3d 515, 521-23 (4th Cir.2005) (<HOLDING>); see Shepard v. United States, 544 U.S. 13,
holding that when a defendant admits prior convictions at a habitual offender hearing he waives any complaints about the validity of the prior convictions holding that where defendant did not dispute any of the facts supporting the career offender status in district court there is no constitutional violation in relying on defendants prior convictions holding that application of career offender enhancement falls within exception for prior convictions where facts are undisputed making it unnecessary for district court to engage in further fact finding about prior convictions holding that where defendant did not dispute any facts supporting the career offender status in district court there is no constitutional violation in relying on defendants prior convictions holding that defendants sixth amendment right to trial by a jury was not violated by district courts reliance on his prior convictions for purposes of sentencing as career offender