parse (Mime::Type)

    # File lib/action_controller/mime_type.rb, line 88
          def parse(accept_header)
            if accept_header !~ /,/
              [Mime::Type.lookup(accept_header)]
            else
              # keep track of creation order to keep the subsequent sort stable
              list = []
              accept_header.split(/,/).each_with_index do |header, index|
                params, q = header.split(/;\s*q=/)
                if params
                  params.strip!
                  list << AcceptItem.new(index, params, q) unless params.empty?
                end
              end
              list.sort!

              # Take care of the broken text/xml entry by renaming or deleting it
              text_xml = list.index("text/xml")
              app_xml = list.index(Mime::XML.to_s)

              if text_xml && app_xml
                # set the q value to the max of the two
                list[app_xml].q = [list[text_xml].q, list[app_xml].q].max

                # make sure app_xml is ahead of text_xml in the list
                if app_xml > text_xml
                  list[app_xml], list[text_xml] = list[text_xml], list[app_xml]
                  app_xml, text_xml = text_xml, app_xml
                end

                # delete text_xml from the list
                list.delete_at(text_xml)

              elsif text_xml
                list[text_xml].name = Mime::XML.to_s
              end

              # Look for more specific XML-based types and sort them ahead of app/xml

              if app_xml
                idx = app_xml
                app_xml_type = list[app_xml]

                while(idx < list.length)
                  type = list[idx]
                  break if type.q < app_xml_type.q
                  if type.name =~ /\+xml$/
                    list[app_xml], list[idx] = list[idx], list[app_xml]
                    app_xml = idx
                  end
                  idx += 1
                end
              end

              list.map! { |i| Mime::Type.lookup(i.name) }.uniq!
              list
            end
          end