12     protected $userAgent = null;  variable in Jaybizzle\\CrawlerDetect\\CrawlerDetect
313     public function __construct(array $headers = null, $userAgent = null)  argument
316         $this->setUserAgent($userAgent);
354      * @param string $userAgent
356     public function setUserAgent($userAgent = null)  argument
358         if (false === empty($userAgent)) {
359             return $this->userAgent = $userAgent;
361             $this->userAgent = null;
364                     $this->userAgent .= $this->httpHeaders[$altHeader].' ';
368             return $this->userAgent = (!empty($this->userAgent) ? trim($this->userAgent) : null);
395      * @param string $userAgent
399     public function isCrawler($userAgent = null)  argument
401         $agent = is_null($userAgent) ? $this->userAgent : $userAgent;