# File lib/rack/request.rb, line 376
      def parse_http_accept_header(header)
        header.to_s.split(/\s*,\s*/).map do |part|
          attribute, parameters = part.split(/\s*;\s*/, 2)
          quality = 1.0
          if parameters and /\Aq=([\d.]+)/ =~ parameters
            quality = $1.to_f
          end
          [attribute, quality]
        end
      end