parse

# File actionpack/lib/action_dispatch/http/mime_type.rb, line 176
      def parse(accept_header)
        if !accept_header.include?(',')
          accept_header = accept_header.split(PARAMETER_SEPARATOR_REGEXP).first
          parse_trailing_star(accept_header) || [Mime::Type.lookup(accept_header)].compact
        else
          list, index = AcceptList.new, 0
          accept_header.split(',').each do |header|
            params, q = header.split(PARAMETER_SEPARATOR_REGEXP)
            if params.present?
              params.strip!

              params = parse_trailing_star(params) || [params]

              params.each do |m|
                list << AcceptItem.new(index, m.to_s, q)
                index += 1
              end
            end
          end
          list.assort!
        end
      end