+my $state64 = Digest::HighwayHash->new([1, 2, 3, 4]);
+my $state128 = Digest::HighwayHash->new([1, 2, 3, 4]);
+my $state256 = Digest::HighwayHash->new([1, 2, 3, 4]);
+
+$state64->append('hello');
+$state64->append('');
+$state128->append('h');
+$state128->append('ell');
+$state128->append('o');
+$state256->append('hell');
+$state256->append('o');
+
+is $state64->finish64, '11956820856122239241', 'finish64';
+is_deeply $state128->finish128, ['3048112761216189476', '13900443277579286659'], 'finish128';
+is_deeply $state256->finish256, ['8099666330974151427', '17027479935588128037', '4015249936799013189', '10027181291351549853'], 'finish256';
+