Case C-174/18: Judgment of the Court (Ninth Chamber) of 14 March 2019 (request for a preliminary ruling from the Tribunal de première instance de Liège — Belgium) — Jean Jacob, Dominique Lennertz v État belge (Reference for a preliminary ruling — Freedom of movement for workers — Equal treatment — Income tax — Legislation for the avoidance of double taxation — Pension received in a Member State other than that of residence — Method of calculating the exemption in the Member State of residence — Loss of part of the benefit of certain tax advantages)