private function extractResults($resultSet)
    {
        foreach ($resultSet['results'] as $result) {
            foreach ($result['data'] as $data) {
                if (isset($data['graph'])) {
                    foreach ($data['graph']['nodes'] as $node) {
                        $this->nodesMap[$node['id']] = $node;
                    }
                    foreach ($data['graph']['relationships'] as $rel) {
                        $this->relationshipsMap[$rel['id']] = $rel;
                    }
                }
            }
        }
    }