ADDED you can now use relative resources

browser.resources.fail("/form/post") instead of
browser.resources.fail("/form/post")

Resource URLs can be absolute or relative.  Relative URLs will match
any request with the same path, so only use relative URLs that are
specific to a given request.
ADDED DNS masking

Browser.dns.localhost('*.example.com');
Browser.defaults.site = 'http://example.com:3000';

browser = new Browser();
browser.visit('/here', function(error, browser) {
  browser.assert.url('http://example.com:3000/here');
});
Added test cases for DNS mask