040000 tree 54abf26a6f4cd1cdf9fc14af09e671174d0ab1f4	exceptions
040000 tree 72508828f152af5b912d79843fc27efd6d8474d2	protocol
040000 tree 615ab4bd456bc57818d627d0ff769284956c8be8	types
040000 tree 14dc2c58fab2238a97f55bc3429043e41297b112	util