public function removeUsersWithRole(Site $site, $userIdList, $role = null)
    {
        $q = $this
            ->db
            ->delete('ucms_site_access')
            ->condition('site_id', $site->id)
            ->condition('uid', $userIdList)
        ;

        if ($role) {
            $q->condition('role', $role);
        }

        $q->execute();

        $this->resetCache();
    }