Вы пытались создать класс, который расширяется от \Swift_Message
?
/**
* Class CustomSwiftMessage
*/
public class CustomSwiftMessage extends \Swift_Message
{
/**
* @var string
*/
private $source_ip;
/**
* Constructor
*/
public function __construct($subject = null, $body = null, $contentType = null, $charset = null, $source_ip = null)
{
parent::__construct($subject, $body, $contentType, $charset);
$this->source_ip = $source_ip;
}
/**
* Set source_ip
* @param string $source_ip
* @return this
*/
public function setSourceIp($source_ip)
{
$this->source_ip = $source_ip;
return $this;
}
/**
* Get source_ip
*/
public function getSourceIp()
{
return $this->source_ip;
}
}