/**
  * @param string    $message
  * @param int       $code
  * @param Exception $previous
  */
 public function __construct($message = null, $code = null, $previous = null)
 {
     if ($code == null) {
         $code = Protocol::HTTP_SERVER_ERROR;
     }
     parent::__construct($message, $code, $previous);
 }
 /**
  * @param string    $message
  * @param int       $code
  * @param Exception $previous
  */
 public function __construct($message = null, $code = null, $previous = null)
 {
     if ($code == null) {
         $code = Protocol::CLOSE_GOING_AWAY;
     }
     parent::__construct($message, $code, $previous);
 }