040000 tree b7b30996e8d8a6da86b088d2acdb96b884b3fe41	impls
040000 tree 4dbcbd62e12ffb181645a85d39549b92d721e2a1	non_integer_base
040000 tree e878babc38428e9e5bdb9543607512b0b5cefd13	visibility