Case T-263/15 RENV: Judgment of the General Court of 21 December 2021 — Gmina Miasto Gdynia and Port Lotniczy Gdynia Kosakowo v Commission (State aid — Airport infrastructure — Public funding by the municipalities of Gdynia and Kosakowo for setting up the Gdynia-Kosakowo Airport — Decision declaring the aid incompatible with the internal market and ordering its recovery — Advantage — Market economy operator principle — Effect on trade between Member States — Adverse effect on competition — Recovery — Withdrawal of a decision — Failure to re-open the formal investigation procedure — Procedural rights of the interested parties — Rights of the defence — Obligation to state reasons)