In People v. Glasper, 234 Ill. 2d 173, 917 N.E.2d 401, 334 Ill. Dec. 575 (2009), our supreme court provided violation of a supreme court rule does not always mandate reversal as such an error relates to a right created only by the court, not a fundamental right or constitutional protection. Glasper, 234 Ill. 2d at 193, 917 N.E.2d at 414. Significantly, the original Rule 431(b) only extended the right in question to defendants who specifically requested it. Glasper, 234 Ill. 2d at 193, 917 N.E.2d at 413-14. Under both versions of the rule, the supreme court provided trial courts "shall" question potential jurors where the rule is applicable. 177 Ill. 2d R. 431(b); Official Reports Advance Sheet No. 8 (April 11, 2007), R. 431(b), eff. May 1, 2007. Because the amendment to Rule 431(b) merely changed the application of the rule from optional to automatic, and not the obligations of the trial court once the rule is invoked, we consider Glasper's rationale in the present case. In Glasper, our supreme court considered a trial court's failure, after informing jurors of all four Rule 431(b) principles, to question them on the fourth principle, whether they would hold against defendant his decision not to testify. Glasper, 234 Ill. 2d at 188-89, 917 N.E.2d at 411. The defendant in Glasper argued the trial court's failure to comply with Rule 431(b) deprived him of his sixth-amendment rights and warranted automatic reversal because the impact of the error could not be measured. Glasper, 234 Ill. 2d at 189, 917 N.E.2d at 412. The State countered that any error was harmless because the evidence against defendant was overwhelming. Glasper, 234 Ill. 2d at 189-90, 917 N.E.2d at 412. The State further argued the United States Supreme Court does not recognize this type of error as a structural error that mandates automatic reversal. Glasper, 234 Ill. 2d at 191, 917 N.E.2d at 412. Our supreme court agreed with the State, noting the United States Supreme Court recognizes errors as structural in a very limited group of cases. Glasper, 234 Ill. 2d at 198, 917 N.E.2d at 416. While Glasper framed its analysis in terms of structural error instead of plain error, our supreme court explained in Blue the grounds for reversal based on structural error are the same as the second prong of the plain-error doctrine. Glasper determined the trial court's error did not rise to the level of structural error because the error did not involve a fundamental right or a constitutional protection. Glasper, 234 Ill. 2d at 199-200, 917 N.E.2d at 417-18. Glasper acknowledged it would not hesitate to reverse a defendant's conviction if the facts showed that the failure to abide by Zehr resulted in the defendant's conviction by a biased jury. Glasper, 234 Ill. 2d at 200-01, 917 N.E.2d at 418. Further, Glasper emphasized its holding is "limited to the version of Rule 431(b)(4) that was in effect at the time of that trial, and would not necessarily apply to subsequent versions of the rule." Glasper, 234 Ill. 2d at 200, 917 N.E.2d at 418.