May a court of appeals exercise pendent appellate jurisdiction to consider an issue, such as standing, that 'significantly overlaps' with an immediately appealable collateral order, such as state sovereign immunity under the Eleventh Amendment, but is not 'essential to the resolution of [a] properly appealed collateral order[]?

QUESTION PRESENTED In Swint v. Chambers Cnty. Comm'n, 514 U.S. 35, 51 (1995), this Court noted in dicta that it may be appropriate for a court of appeals to exercise pendent appellate jurisdiction over an issue that is otherwise not immediately appealable under narrow circumstances where the non-appealable issue is “inextricably intertwined” with an immediately appealable collateral order or where review of the former is “necessary to ensure meaningful review” of the latter. The question presented is: May a court of appeals exercise pendent appellate jurisdiction to consider an issue, such as standing, that “significantly overlaps” with an immediately appealable collateral order, such as state sovereign immunity under the Eleventh Amendment, but is not “essential to the resolution of [a] properly appealed collateral order[]”?