Case C-509/17: Judgment of the Court (Third Chamber) of 16 May 2019 (request for a preliminary ruling from the Arbeidshof te Antwerpen — Belgium) — Christa Plessers v PREFACO NV, Belgische Staat (Reference for a preliminary ruling — Transfers of undertakings — Directive 2001/23/EC — Articles 3 to 5 — Safeguarding of employees’ rights — Exceptions — Insolvency proceedings — Proceedings for judicial restructuring by transfer under judicial supervision — Total or partial safeguard of the undertaking — National legislation authorising the transferee, after the transfer, to choose which employees to keep on)