I changed (again) the way the assertions are made, hopefully providing a better feedback, now (reset the trainer if you don't see any difference)

yeah, I feared a bit about that type of cases, where the message becomes a bit misleading... The problem is that the real count is:

("'vxn", 10)
('ansace', 12)
("das'", 20)      <<<< you're returning "das" instead, which isn't present in the count so has a 0 frequency.
("dtqo'a", 15)
('fhuubd', 3)
('lunceifkq', 2)
('yyaqfy', 24)

IIRC the strings should be split like "sie@##@1/1/1fsefsef" == ["sie", "fsefsef"], so no, you're wrong.

handled