# File lib/em-http/middleware/oauth.rb, line 16
      def request(client, head, body)
        request = client.req
        uri     = request.uri.join(encode_query(request.uri, request.query))
        params  = {}

        # from https://github.com/oauth/oauth-ruby/blob/master/lib/oauth/request_proxy/em_http_request.rb
        if ["POST", "PUT"].include?(request.method)
          head["content-type"] ||= "application/x-www-form-urlencoded" if body.is_a? Hash
          form_encoded = head["content-type"].to_s.downcase.start_with?("application/x-www-form-urlencoded")

          if form_encoded
            CGI.parse(client.normalize_body(body)).each do |k,v|
              # Since `CGI.parse` always returns values as an array
              params[k] = v.size == 1 ? v.first : v
            end
          end
        end

        head["Authorization"] = SimpleOAuth::Header.new(request.method, uri, params, @opts)

        [head,body]
      end