public function parse()
{
if (empty($this->engine)) {
return '';
}
preg_match("~{$this->engine}\\s*/?\\s*((?(?=\\d+\\.\\d)\\d+[.\\d]*|\\d{1,7}(?=(?:\\D|\$))))~i", $this->userAgent, $matches);
if (!$matches) {
return '';
}
return array_pop($matches);
}