private function prepareReachableCenterByUser()
    {
        $groupCenters = $this->user->getGroupCenters();
        
        foreach ($groupCenters as $groupCenter) {
            
            $center = $groupCenter->getCenter();
            
            if (!array_key_exists($center->getId(), 
                    $this->reachableCenters)) {
                $this->reachableCenters[$center->getId()] = $center;
            }
        }
    }