/**
  * @param Filesystem                  $files
  * @param ServiceInterpreterInterface $interpreter
  * @param ResponseMergerInterface     $responseMerger
  * @param Ssh2SftpConnectionInterface $sshConnection        optional
  */
 public function __construct(Filesystem $files = null, ServiceInterpreterInterface $interpreter = null, ResponseMergerInterface $responseMerger = null, Ssh2SftpConnectionInterface $sshConnection = null)
 {
     if (!is_null($sshConnection)) {
         $this->ssh = $sshConnection;
     }
     parent::__construct($files, $interpreter, $responseMerger);
 }