Case T-607/17: Judgment of the General Court of 13 May 2020 — Volotea v Commission (State aid — Aviation sector — Aid granted by Italy to Sardinian airports — Decision declaring the aid compatible in part and incompatible in part with the internal market — Whether imputable to the State — Recovery — Beneficiaries — Advantage to co-contracting airlines — Market economy operator principle — Selectivity — Effect on trade between Member States — Adverse effect on competition — Recovery — Legitimate expectations — Obligation to state reasons)