Case C-311/21: Judgment of the Court (Second Chamber) of 15 December 2022 (request for a preliminary ruling from the Bundesarbeitsgericht — Germany) — CM v TimePartner Personalmanagement GmbH (Reference for a preliminary ruling — Employment and social policy — Temporary agency work — Directive 2008/104/EC — Article 5 — Principle of equal treatment — Need to respect, in the event of derogation from that principle, the overall protection of temporary agency workers — Collective agreement providing for lower pay than that of staff recruited directly by the user undertaking — Effective judicial protection — Judicial review)