International organizations — Personality — Legal personality of international organizations in English law — Organization granted the legal capacities of a body corporate — Whether organization thus created a body corporate — Whether capacities of a body corporate include capacity to incur contractual liabilities on own account — Whether members liable for contracts concluded in the name of the organization — International Tin Council — Sixth International Tin Agreement, 1982 — International Tin Council-United Kingdom Headquarters Agreement, 1972 — International Tin Council (Immunities and Privileges) Order 1972 — The law of England