Case C-422/20: Judgment of the Court (Sixth Chamber) of 9 September 2021 (request for a preliminary ruling from the Oberlandesgericht Köln — Germany) — RK v CR (Reference for a preliminary ruling — Judicial cooperation in civil matters — Succession — Regulation (EU) No 650/2012 — Article 6(a) — Declining of jurisdiction — Article 7(a) — Jurisdiction — Examination by the court second seised — Article 22 — Choice of law applicable — Article 39 — Mutual recognition — Article 83(4) — Transitional provisions)