Added in inital solution but user should implement it.

Added in preloaded section.

I wanted to give up, but I see this comment. I didn't thought that there may be an equation for that.

Reraised above with more detail

Added

@FArekkusu

I think it's just another way of stating the issue you raised.

Not an issue.

1. Maybe Test.expect_error worked badly in the past but now everything is alright, and no exception handling is required on the user's side.
2. Rewrote the task to accept a file path instead of the file handler.

That isn't an issue.

Fixed it the right way. Old solutions should be revalidated sooner or later.

Fixed.

Fixed Python version.

It annihilated all current solutions because function name is changed, but whatever.

Right suggestion, taking [] is allowed now.
Other rules still apply.