RecursiveIteratorIterator fatal error

$url = 'https://maps.googleapis.com/maps/api/geocode/json?latlng=40.714224,-73.961452';
$client = new \GuzzleHttp\Client;
$response = $client->get($url, [
  'headers' => ['Accept' => 'application/json'],
])->getBody();
$array = json_decode($response, TRUE);
$iterator = new \RecursiveIteratorIterator(
  new \RecursiveArrayIterator($array),
  \RecursiveIteratorIterator::SELF_FIRST);
// Recurse through the result array. When there is an array of items at the
// expected depth that has the expected identifier as one of the keys, pull that
// array out as a distinct item.
$identifier = 'place_id';
$identifierDepth = 1;
$items = [];
while ($iterator->valid()) {
  $item = $iterator->current();  // Segfaults on last row from gmap data.
  if (is_array($item)) {
    if (array_key_exists($identifier, $item)) {
      if ( $iterator->getDepth() == $identifierDepth) {
        $items[] = $item;
      }
    }
  }
  $iterator->next();
}

echo 'no error';