Case C-567/15: Judgment of the Court (Fourth Chamber) of 5 October 2017 (request for a preliminary ruling from the Vilniaus apygardos teismas — Lithuania) — ‘LitSpecMet’ UAB v ‘Vilniaus lokomotyvų remonto depas’ UAB (Reference for a preliminary ruling — Public works contracts, public supply contracts and public service contracts — Directive 2004/18/EC — Article 1(9) — Concept of contracting authority — Company wholly owned by a contracting authority — Transactions internal to the group)