protected function skip_row($capability) {
        $perm = $this->permissions[$capability->name];
        if ($perm == CAP_INHERIT) {
            // Do not print empty rows in role overview, admins need to know quickly what is allowed and prohibited,
            // if they want to see the list of all capabilities they can go to edit role page.
            return true;
        }
        parent::skip_row($capability);
    }