* domain names, and even `localhost` when connecting from the server itself. Each of a web server's
 * names is a distinct URL and they are not interchangeable. For example, even if
 * `http://square.github.io/dagger` and `http://google.github.io/dagger` are served by the same IP
 * address, the two URLs identify different resources.
 *
 * ### Port
 *
 * The port used to connect to the web server. By default this is 80 for HTTP and 443 for HTTPS.