Case C-653/18: Judgment of the Court (Tenth Chamber) of 17 October 2019 (request for a preliminary ruling from the Naczelny Sąd Administracyjny — Poland) — Unitel Sp. z o.o. w Warszawie v Dyrektor Izby Skarbowej w Warszawie (Reference for a preliminary ruling — Taxation — Value added tax (VAT) — Directive 2006/112/EC — Article 146 — Exemptions on exportation — Concept of ‘supply of goods’ — Article 131 — Conditions laid down by the Member States — Principle of proportionality — Principle of fiscal neutrality — Evidence — Tax evasion — Practice of a Member State consisting in refusing the right to exemption where the person acquiring the goods exported is not identified)