__construct() публичный Метод

Details may be optionally provided to the constructor.
public __construct ( string | Swift_OutputByteStream $data = null, string $filename = null, string $contentType = null )
$data string | Swift_OutputByteStream
$filename string
$contentType string
 /**
  * Calendar attachment constructor
  *
  * @param Calendar $calendar
  */
 public function __construct(Calendar $calendar)
 {
     $data = $calendar->createCalendar();
     $filename = $calendar->getConfig('filename');
     $contentType = $calendar->getContentType();
     parent::__construct($data, $filename, $contentType);
 }