not conjectural or hypothetical.]” Lujan v. Defenders of Wildlife, 504 U.S. 555, 560-61, 112 S.Ct. 2130, 119 L.Ed.2d 351 (1992) (internal citation, quotation marks, and footnote omitted). 4 . “[W]e recognize that a district court always has jurisdiction to impose sanctions designed to enforce its own rules, even after that court no longer has jurisdiction over the substance of a case[.]” Fleming & Assocs. v. Newby & Tittle, 529 F.3d 631, 637 (5th Cir.2008). " ‘It is well established that a federal court may consider collateral issues after an action is no longer pending.’ ” Id. at 637-38 (quoting Cooter & Gell v. Hartmarx Corp., 496 U.S. 384, 395, 110 S.Ct. 2447, 110 L.Ed.2d 359 (1990)); see also Willy v. Coastal Corp., 503 U.S. 131, 137-39, 112 S.Ct. 1076, 117 L.Ed.2d 280 (1992) (<HOLDING>). 5 . Although Appellees moved for Rule 11
holding that district court had subjectmatter jurisdiction and yet that judgment void for lack of jurisdiction to render the particular judgment holding that a district court could constitutionally impose rule 11 sanctions in a case in which was later determined that the court lacked subject matter jurisdiction holding that a district court may impose sanctions for abuse of judicial process pursuant to rule 11 even after it is determined that the court lacked subject matter jurisdiction over the plaintiffs claims holding that a district court had jurisdiction to impose rule 11 sanctions regardless of the existence of subjectmatter jurisdiction holding that courts of appeals should review all aspects of the district courts rule 11 determination for abuse of discretion and noting that the district court has broad discretion to impose rule 11 sanctions