Joined Cases C-138/17 P and C-146/17 P: Judgment of the Court (First Chamber) of 13 December 2018 — European Union, represented by the Court of Justice of the European Union v Gascogne Sack Deutschland GmbH, formerly Sachsa Verpackung GmbH, Gascogne SA, European Commission (C-138/17), Gascogne Sack Deutschland GmbH, Gascogne SA v European Union, represented by the Court of Justice of the European Union, European Commission (C-146/17) (Appeal — Actions for damages — Second paragraph of Article 340 TFEU — Excessive duration of the proceedings in two cases before the General Court of the European Union — Damage allegedly suffered by the applicants — Material damage — Bank guarantee charges — Causal link — Default interest — Non material damage)