Case C-561/20: Judgment of the Court (Fourth Chamber) of 7 April 2022 (request for a preliminary ruling from the Nederlandstalige ondernemingsrechtbank Brussel — Belgium) — Q, R, S v United Airlines Inc. (Reference for a preliminary ruling — Air transport — Regulation (EC) No 261/2004 — Common rules on compensation and assistance to passengers in the event of denied boarding and of cancellation or long delay of flights — Connecting flight consisting of two legs — Significant delay to final destination caused in the second leg of that flight linking two airports in a third country — Validity of that regulation under international law)