040000 tree 54abf26a6f4cd1cdf9fc14af09e671174d0ab1f4	exceptions
040000 tree f2e1f8164e4fc35234dd831a3906f0599c97a5a7	protocol
040000 tree f16731de40195d6fe8de109c679e937ae798d347	types
040000 tree 14dc2c58fab2238a97f55bc3429043e41297b112	util