private function buildPermissionList($confId)
 {
     $permissions = [];
     foreach (PermissionNames::AllConferencePermissions($confId) as $pname) {
         $this->checkAddPermission($pname, $permissions);
     }
     foreach (Event::where('conferenceID', $confId)->get() as $e) {
         if (Entrust::can(PermissionNames::EventDetailView($e->id))) {
             $permissions[] = 'conference-view-event-reports';
             break;
         }
     }
     return $permissions;
 }