I upgraded our app from rails 3.0.10 to rails 3.1, but I found that
the helper call 'sites_path(@site, :domain => a_domain)' won't
generate the url I want, I actually want something like '/sites/1?
domain=a_domain', but query parameter 'domain' is missing from the
url. I found that Rails 3.1 introduced a new option called 'domain'
for url_for: http://guides.rubyonrails.org/3_1_release_notes.html#action-dispatch.
I am curious if we can still add query parameter called 'domain' in