Unregister fix

Signed-off-by: Frca <killerfrca@gmail.com>
Properly implement display higlighted exam

Signed-off-by: Frca <killerfrca@gmail.com>
Check classmates validity in response

Signed-off-by: Frca <killerfrca@gmail.com>
Little cleanup in code and imports

Signed-off-by: Frca <killerfrca@gmail.com>