s premised on the existence of a federal question, that "[d]efective allegations of jurisdiction may be amended, upon terms, in the trial or appellate courts." 00 U.S.C. § 0000. Although the defect in [plaintiff's] allegations must be cured by supplemental pleading, instead of amended pleading, the statutory purpose of avoiding needless sacrifice to defective pleading applies equally to this case. Mathews, 000 U.S. at 00 n. 0, 00 S.Ct. at 0000 n. 0