Extradition — Treaties — Relationship of extradition treaty and domestic legislation governing extradition — Whether statutory provisions can be limited or extended by extradition treaty — Arrest and detention of accused pending receipt of formal extradition request — Statute requiring magistrate to set time-limit for receipt of formal extradition request or discharge of accused in absence of request — Time-limit to be reasonable in the circumstances — Treaty providing for forty-five-day period from arrest for submission of formal request — Whether requesting State entitled to full forty-five-day period — United Kingdom — United States Extradition Treaty, 1972 — The law of the Cayman Islands