Message::__construct PHP Method

    public function __construct($msg)
    {
        $this->msg = $msg;
    }

 /**
  * Constructor for SAML 2 response messages.
  *
  * @param string          $tagName The tag name of the root element.
  * @param \DOMElement|null $xml     The input message.
  * @throws \Exception
  */
 protected function __construct($tagName, \DOMElement $xml = null)
 {
     parent::__construct($tagName, $xml);
     $this->status = array('Code' => Constants::STATUS_SUCCESS, 'SubCode' => null, 'Message' => null);
     if ($xml === null) {
         return;
     }
     if ($xml->hasAttribute('InResponseTo')) {
         $this->inResponseTo = $xml->getAttribute('InResponseTo');
     }
     $status = Utils::xpQuery($xml, './saml_protocol:Status');
     if (empty($status)) {
         throw new \Exception('Missing status code on response.');
     }
     $status = $status[0];
     $statusCode = Utils::xpQuery($status, './saml_protocol:StatusCode');
     if (empty($statusCode)) {
         throw new \Exception('Missing status code in status element.');
     }
     $statusCode = $statusCode[0];
     $this->status['Code'] = $statusCode->getAttribute('Value');
     $subCode = Utils::xpQuery($statusCode, './saml_protocol:StatusCode');
     if (!empty($subCode)) {
         $this->status['SubCode'] = $subCode[0]->getAttribute('Value');
     }
     $message = Utils::xpQuery($status, './saml_protocol:StatusMessage');
     if (!empty($message)) {
         $this->status['Message'] = trim($message[0]->textContent);
     }
 }