public function connect()
{
$this->dispatcher->dispatch(TransporterEvents::TRANSPORTER_CONNECT, new TransporterEvent($this));
$port = $this->port ?: 22;
$success = $this->sftp->connect($this->host, $port);
if (false === $success) {
throw new \RuntimeException(sprintf('Could not connect to host %s on port %s', $this->host, $port));
}
}