why fixed_length = fixed_length * 4 in passkey.py?

[YEOMJINSEOP]

Hi, @Sakits! Thanks for sharing amazing work again.

i have a question regarding pass key retrieval task.

in passkey.py, fixed_length is multiplied with 4, (fixed_length = fixed_length * 4)
and i observe n_garbage_prefix incrases as 400, 800, 1200, ..., 34000, ...

Could you explain why fixed_length is multiplied by 4? Is there a specific reason or intention behind this?
(If multiplying with 4 is for making a fixed_length to a number of tokens, does setting fixed_length=10k equals to 40k tokens?)

Thank you!