private function injectSessionSubscriber($client, $config)
{
if (isset($config['session.storage']) && $config['session.storage'] instanceof Session\Storage) {
$sessionStorage = $config['session.storage'];
} else {
$sessionStorage = new Api\Session\Storage\Memory();
}
$username = isset($config['user']) ? $config['user'] : null;
$sessionSubscriber = new Api\Session\Subscriber($sessionStorage, $username);
$client->addSubscriber($sessionSubscriber);
}