public function execute()
 {
     if ($this->Url == null) {
         return '';
     }
     $content = HttpLoader::get($this->Url, $this->RandomAgents, $this->PostData);
     switch ($this->Format) {
         case "json":
             $content = json_decode($content);
             break;
     }
     return $content;
 }
 public function execute($pid = null)
 {
     $url = null;
     $postData = null;
     if ($pid != null) {
         if (isset($this->Urls[$pid])) {
             $url = $this->Urls[$pid];
         }
         if (isset($this->PostDatas[$pid])) {
             $postData = $this->PostDatas[$pid];
         }
     } else {
         $url = $this->Url;
     }
     $content = HttpLoader::get($url, $this->RandomAgents, $postData);
     switch ($this->Format) {
         case "json":
             $content = json_decode($content);
             break;
     }
     return $content;
 }