host_or_subdomain_and_domain

# File actionpack/lib/action_dispatch/http/url.rb, line 70
        def host_or_subdomain_and_domain(options)
          return options[:host] if !named_host?(options[:host]) || (options[:subdomain].nil? && options[:domain].nil?)

          tld_length = options[:tld_length] || @@tld_length

          host = ""
          unless options[:subdomain] == false
            host << (options[:subdomain] || extract_subdomain(options[:host], tld_length)).to_param
            host << "."
          end
          host << (options[:domain] || extract_domain(options[:host], tld_length))
          host
        end