040000 tree 54abf26a6f4cd1cdf9fc14af09e671174d0ab1f4	exceptions
040000 tree 72508828f152af5b912d79843fc27efd6d8474d2	protocol
040000 tree 59f6f708f337744029b103cf38ddd8e8d82940c2	types
040000 tree b0772ea7491169e2f0a1dc2dddba6170c3363db4	util