Did the court of appeals err in denying petitioner's motion for a certificate of appealability to review the denial of an evidentiary hearing on petitioner's 28 U.S.C. § 2255 claim that counsel improperly stipulated to a severe increase in punishment?

QUESTION PRESENTED In McCoy v. Louisiana, 138 8.Ct. 1500 (2018), this Court held that trial counsel may not concede the defendant’s guilt over the defendant’s objection. In petitioner’s case, defense counsel conceded applicability of a sentencing guideline enhancement despite petitioner’s having specifically negotiated for the right to object to the enhancement as part of his plea bargain and despite the absence of evidence to support the enhancement. Did the court of appeals err in denying petitioner’s motion for a certificate of appealability to review the denial of an evidentiary hearing on petitioner’s 28 U.S.C. § 2255 claim that counsel improperly stipulated to a severe increase in punishment? @)