Case C-823/18 P: Judgment of the Court (Second Chamber) of 25 November 2020 — European Commission v GEA Group AG (Appeal — Agreements, decisions and concerted practices — European markets for tin-based heat stabilisers and for heat stabilisers with epoxised soybean oil and esters as their base — Price fixing, market allocation and exchange of commercially sensitive information — Application of the ceiling of 10 % of turnover to one of the entities forming the undertaking — Annulment of the decision amending the fine imposed in the initial infringement decision — Fines — Concept of an ‘undertaking’ — Joint and several liability for payment of the fine — Principle of equal treatment — Date on which the fine is payable in the event of amendment)