public function canEdit($member = null)
    {
        $managedSites = Multisites::inst()->sitesManagedByMember();
        if (count($managedSites) && in_array($this->owner->SiteID, $managedSites)) {
            // member has permission to manage MultisitesAware objects on this site,
            // hand over to the object's canEdit method
            return null;
        } else {
            // member does not have permission to edit objects on this object's Site
            return false;
        }
    }