`VALUE_OPTIONAL` should also be changed. It's not optional because just specifying `--method` doesn't make sense.
So instead it should be required and specify a default (`GET`) for it (fifth argument AFAIK).
The same also applies for host (`localhost`). These are the defaults of https://github.com/symfony/symfony/blob/master/src/Symfony/Component/Routing/RequestContext.php as well.

Also it would be nice to add one more option: scheme (defaults to `http`).