Swift_Image::newInstance PHP Method

    public static function newInstance($data = null, $filename = null, $contentType = null)
    {
        return new self($data, $filename, $contentType);
    }

 public function testEmbeddedFilesWithMultipartDataCreateMultipartRelatedContentAsAnAlternative()
 {
     $message = Swift_Message::newInstance();
     $message->setCharset('utf-8');
     $message->setSubject('test subject');
     $message->addPart('plain part', 'text/plain');
     $image = Swift_Image::newInstance('<image data>', 'image.gif', 'image/gif');
     $cid = $message->embed($image);
     $message->setBody('<img src="' . $cid . '" />', 'text/html');
     $message->setTo(array('*****@*****.**' => 'User'));
     $message->setFrom(array('*****@*****.**' => 'Other'));
     $message->setSender(array('*****@*****.**' => 'Other'));
     $id = $message->getId();
     $date = preg_quote(date('r', $message->getDate()), '~');
     $boundary = $message->getBoundary();
     $cidVal = $image->getId();
     $this->assertRegExp('~^' . 'Sender: Other <*****@*****.**>' . "\r\n" . 'Message-ID: <' . $id . '>' . "\r\n" . 'Date: ' . $date . "\r\n" . 'Subject: test subject' . "\r\n" . 'From: Other <*****@*****.**>' . "\r\n" . 'To: User <*****@*****.**>' . "\r\n" . 'MIME-Version: 1.0' . "\r\n" . 'Content-Type: multipart/alternative;' . "\r\n" . ' boundary="' . $boundary . '"' . "\r\n" . "\r\n\r\n" . '--' . $boundary . "\r\n" . 'Content-Type: text/plain; charset=utf-8' . "\r\n" . 'Content-Transfer-Encoding: quoted-printable' . "\r\n" . "\r\n" . 'plain part' . "\r\n\r\n" . '--' . $boundary . "\r\n" . 'Content-Type: multipart/related;' . "\r\n" . ' boundary="(.*?)"' . "\r\n" . "\r\n\r\n" . '--\\1' . "\r\n" . 'Content-Type: text/html; charset=utf-8' . "\r\n" . 'Content-Transfer-Encoding: quoted-printable' . "\r\n" . "\r\n" . '<img.*?/>' . "\r\n\r\n" . '--\\1' . "\r\n" . 'Content-Type: image/gif; name=image.gif' . "\r\n" . 'Content-Transfer-Encoding: base64' . "\r\n" . 'Content-Disposition: inline; filename=image.gif' . "\r\n" . 'Content-ID: <' . $cidVal . '>' . "\r\n" . "\r\n" . preg_quote(base64_encode('<image data>'), '~') . "\r\n\r\n" . '--\\1--' . "\r\n" . "\r\n\r\n" . '--' . $boundary . '--' . "\r\n" . '$~D', $message->toString());
 }