normalize_host

# File actionpack/lib/action_dispatch/http/url.rb, line 112
        def normalize_host(options)
          return options[:host] if !named_host?(options[:host]) || same_host?(options)

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

          host = ""
          if options[:subdomain] == true || !options.key?(:subdomain)
            host << extract_subdomain(options[:host], tld_length).to_param
          elsif options[:subdomain].present?
            host << options[:subdomain].to_param
          end
          host << "." unless host.empty?
          host << (options[:domain] || extract_domain(options[:host], tld_length))
          host
        end