public function getStackedData($delete = true)
    {
        $http = $this->initStackSession();
        $stackedData = $http->getSessionValue($this->stackSessionNamespace);
        if ($delete) {
            $http->deleteSessionValue($this->stackSessionNamespace);
        }

        $datasets = array();
        if ($this->isDataPersisted() && !$this->stackAlwaysUseSessionStorage) {
            foreach ($stackedData as $id => $data) {
                $datasets[$id] = $this->getStorage()->get($id);
            }
        } else {
            $datasets = $stackedData;
        }

        return $datasets;
    }