Case C-647/18: Order of the Court (Sixth Chamber) of 15 January 2020 (request for a preliminary ruling from the Okrazhen sad — Vidin — Bulgaria) — Corporate Commercial Bank, in liquidation v Elit Petrol AD (Reference for a preliminary ruling — Article 53(2) of Rules of Procedure of the Court of Justice — Judicial cooperation in civil matters — Insolvency proceedings — Retroactive amendment to the implementation conditions for reciprocal compensation entered into with a bankrupt credit institution — Rule of law — Principle of legal certainty — Right to an effective remedy)