question: public Hash ( String hex ) { if ( hex . length ( ) != 64 ) { throw new IllegalArgumentException ( "Digest length must be 64 hex characters for Hash" ) ; } this . bytes = ByteUtils . reverse ( ByteUtils . fromHex ( hex ) ) ; }
target:  create a Hash from a hexadecimal representation of the digest Note that this is in the reverse byte order of the internal binary representation.