private function _preparePostRequest($urlPart)
 {
     if ($this->auth === TRUE) {
         $req = new Http_Request($this->baseUrl . $urlPart, array('method' => HTTP_REQUEST_METHOD_POST, 'useBrackets' => FALSE));
         $req->addHeader('Connection', 'Keep-Alive');
         $req->addHeader('Accept', 'application/json');
         $req->setBasicAuth($this->username, $this->password);
         return $req;
     } else {
         throw new Exception("You must authenticate to be able to submit decisions");
     }
 }