Case C-826/19: Judgment of the Court (Fourth Chamber) of 22 April 2021 (request for a preliminary ruling from the Landesgericht Korneuburg — Austria) — WZ v Austrian Airlines AG (Reference for a preliminary ruling — Air transport — Compensation and assistance to passengers in the event of denied boarding and of cancellation or long delay of flights — Regulation (EC) No 261/2004 — Article 6 — Delayed flight — Article 8(3) — Diversion of a flight to an airport serving the same town, city or region — Concept of ‘cancellation’ — Extraordinary circumstances — Compensation to passengers in the event of cancellation or long delay of flights in arrival — Obligation to bear the cost of transferring passengers from the actual airport of arrival to the airport for which the booking was made)