Task fail?

I would like to give some feedback about ...

From: https://checkio.org/mission/letter-queue/solve/

My code works for all the assertions given in the input editor, but keeps failing some weird "Extra" test for no reason. Because the "Extra" test isn't an assertion and doesn't have the code for one (plus I can't scroll to the bottom of it), I can't run checks to see if my code is wrong or the test is wrong.

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