Better variable name

Signed-off-by: Michal Čihař <michal@cihar.com>
Add docblocks

Signed-off-by: Michal Čihař <michal@cihar.com>
Share code in inherited classes

Signed-off-by: Michal Čihař <michal@cihar.com>
Fix commented out test

Signed-off-by: Michal Čihař <michal@cihar.com>