Case C-117/18 P: Judgment of the Court (Fifth Chamber) of 4 December 2019 — PGNiG Supply & Trading GmbH v European Commission (Appeal — Internal market in natural gas — Directive 2009/73/EC — Article 32 — Third-party access — Article 41(6), (8) and (10) — Rules on tariffs — Article 36 — Application for an exemption — Rules governing the operation of the OPAL pipeline — National regulatory authority — Exemption decision — Request for modification — European Commission Decision — Action for annulment — Fourth paragraph of Article 263 TFEU — Admissibility — Decision of no direct concern to the appellant)