Case C-503/18 P: Judgment of the Court (Sixth Chamber) of 6 June 2019 — Inge Barnett v European Economic and Social Committee (Appeal — Civil service — Official — Retirement pension — Early retirement without reduction of pension rights — Staff Regulations of Officials of the European Union — Article 9(2) of Annex VIII — General implementing provisions — Interests of the service — Decision adopted to comply with a judgment of the European Union Civil Service Tribunal — Article 266 TFEU — Res judicata)