Sovereign immunity — Foreign States and their property — Lease of building for use as diplomatic premises — Action for breach of lease — Whether foreign State entitled to jurisdictional immunity — Requirement of close connection between case and forum — Acts iure imperii and iure gestionis — Whether distinction to be made according to nature or purpose of act — Attachment of bank deposits — Immunity from attachment — Whether power of enforcement automatically follows from power to exercise jurisdiction — Whether attachment requires proof of the existence of a debt — Relevance of purpose for which attached funds allocated by State — Whether lack of allocation of State funds for specific purpose renders them liable to attachment — The law of Switzerland