Case C-677/18: Judgment of the Court (Tenth Chamber) of 19 December 2019 (request for a preliminary ruling from the First-tier Tribunal (Tax Chamber) — United Kingdom) — Amoena Ltd v Commissioners for Her Majesty’s Revenue and Customs (Reference for a preliminary ruling — Common Customs Tariff — Tariff classification — Combined Nomenclature — Headings 6212 and 9021 — Mastectomy bras — Implementing Regulation (EU) 2017/1167 — Validity — Notion of ‘accessories’ — Sincere cooperation)