Currently, when ut.expect is executed with a cursor that was closed, no exception is thrown.

I think we should change that behavior as such cursor is invalid and cannot be processed.

I would prefer the call to `ut.expect(closed_cursor) to raise exception.
We do not hide exceptions raised while fetching from cursor (like divisor_equal_to_zero) so I suppose we should not hide that we cannot execute expectation on a closed cursor.

Any thoughts on this? Should we change that behavior?