public function checkout($uri, array $options = [])
{
$uri = stripos($uri, 'unix://') === 0 ? $uri : strtolower($uri);
$options = $options ? array_merge($this->options, $options) : $this->options;
return ($socket = $this->checkoutExistingSocket($uri, $options)) ? new Success($socket) : $this->checkoutNewSocket($uri, $options);
}