Joined Cases C-915/19 to C-917/19: Judgment of the Court (Fifth Chamber) of 28 October 2021 (requests for a preliminary ruling from the Consiglio di Stato — Italy) — Eco Fox Srl (C-915/19), Alpha Trading SpA unipersonale (C-916/19), Novaol Srl (C-917/19) v Fallimento Mythen SpA (C-915/19), Ministero dell’Economia e delle Finanze, Ministero dell’Ambiente e della Tutela del Territorio e del Mare, Ministero delle Politiche agricole, alimentari a forestali, Minsitero dello Svilluppo economico (C-915/19 to C-917/19), Agenzia delle Dogane e dei Monopoli (C-915/19) (Reference for a preliminary ruling — State aid — Biodiesel market — Aid scheme establishing biodiesel quotas exempt from excise duty — Amendment of the authorised aid scheme — Amendment of the quota allocation criteria — Obligation of prior notification to the European Commission — Regulation (EC) No 659/1999 — Article 1(c) — Concept of ‘new aid’ — Regulation (EC) No 794/2004 — Article 4(1) — Concept of ‘alterations to existing aid’)