Case C-408/12 P: Judgment of the Court (Second Chamber) of 4 September 2014 — YKK Corp., YKK Holding Europe BV, YKK Stocko Fasteners GmbH v European Commission (Appeal — Agreements, decisions and concerted practices — Markets for zip fasteners and other fasteners and for attaching machines — Successive responsibilities — Legal upper limit of the fine — Article 23(2) of Regulation No 1/2003 — Concept of ‘undertaking’ — Personal responsibility — Principle of proportionality — Deterrence multiplier)