Treaties — In general — Forms of international agreements — Exchange of notes — Right to conclude treaties — Exchange of notes with a State due to emerge on the dissolution of a Federation of States — Whether concluding an international agreement — Governmental authority empowered to conclude an international agreement — Ratification and entry into force of treaties — Whether ratification necessary for a treaty to come into force — Operation and enforcement of treaties — Necessity for municipal legislation — Whether any operative agreement between the conclusion of the treaty and municipal legislation — Extradition agreement implemented in municipal law after the arrest but before the hearing — Whether extradition agreement applied to the proceedings — The law of South Africa