040000 tree 54abf26a6f4cd1cdf9fc14af09e671174d0ab1f4	exceptions
040000 tree c97a8fdc6385612c0f850257fd848a9d827e3800	protocol
040000 tree bfb85feedcd30403739e70b6727c608df129f054	types
040000 tree aa0acee9ad7184991425ecabc66f4e06fcb5c3a6	util