public function traverse($url = null)
{
if ($url === null) {
$url = $this->baseUrl;
$this->links[$url] = array('links_text' => array('BASE_URL'), 'absolute_url' => $url, 'frequency' => 1, 'visited' => false, 'external_link' => false, 'original_urls' => array($url));
}
$this->traverseSingle($url, $this->maxDepth);
}