def test_level_three_last_time(self):
     self.assertEqual(['a02', 'c09', 'fgf200hjh13', 'abd202', 'b6', 'zx124', 'xyz13', 'b24a52', 'cd100ef12'],
                     str_to_str(['a01', 'c08', 'fgf199hjh12', 'abd201', 'b5', 'zx123', 'xyz12', 'b23a51','cd99ef11']))
 def test_level_three_again(self):
     self.assertEqual(['ab13', 'a6', 'b24a52'],
                     str_to_str(['ab12', 'a5', 'b23a51']))
 def test_absurd_level_three(self):
     self.assertEqual(['ab124', 'ab13', 'gh01', 'ijk9', 'a6','lmn13', 'b24a52', 'cd100ef12'],
         str_to_str(['ab123', 'ab12','gh00', 'ijk8', 'a5','lmn12', 'b23a51','cd99ef11']))
 def test_level_three(self):
     self.assertEqual(['ab124', 'gh01', 'ijk9', 'lmn13', 'cd100ef12'],
                     str_to_str(['ab123', 'gh00', 'ijk8', 'lmn12', 'cd99ef11']))