Default returns a new cors per-route middleware with the default settings: allow all origins, allow methods: GET and POST.

New returns a new cors per-route middleware with the provided options.

WrapNext is the same as New but it is being used to wrap the entire iris' router, even before the method and path matching, i.e: app.WrapRouter(WrapNext(Options{...})).

Options is a configuration container to setup the CORS.