International organizations — Immunity — Jurisdictional immunity — European School in Munich — Legal status — Dispute with parents concerning payment of fees — Whether subject to jurisdiction of German courts — Establishment Protocols concerning European Schools, 1962–75 — Lack of any provision for settlement of disputes by Court of Justice of European Communities or other international tribunal — Whether constituting implicit acceptance of jurisdiction of German courts — Whether charging of school fees contrary to German Constitution — The law of the Federal Republic of Germany