1..9
ok 1 - matches 'abc'
ok 2 - matches 'bca'
ok 3 - matches 'cab'
ok 4 - matches 'cba'
ok 5 - matches 'bac'
ok 6 - matches 'acb'
ok 7 - does not match 'aab'
ok 8 - does not match 'abbc'
ok 9 - does not match 'acc'