Retrieve the upstream content and build an HttpResponse.

def proxy(self):
        """Retrieve the upstream content and build an HttpResponse."""
        headers = self.request.headers.filter(self.ignored_request_headers)
        qs = self.request.query_string if self.pass_query_string else ''

        # Fix for django 1.10.0 bug https://code.djangoproject.com/ticket/27005
        if (self.request.META.get('CONTENT_LENGTH', None) == '' and
                get_django_version() == '1.10'):
            del self.request.META['CONTENT_LENGTH']

        request_kwargs = self.middleware.process_request(
            self, self.request, method=self.request.method, url=self.proxy_url,
            headers=headers, data=self.request.body, params=qs,
            allow_redirects=False, verify=self.verify_ssl, cert=self.cert,
            timeout=self.timeout)

        result = request(**request_kwargs)

        response = HttpResponse(result.content, status=result.status_code)

        # Attach forwardable headers to response
        forwardable_headers = HeaderDict(result.headers).filter(
            self.ignored_upstream_headers)
        for header, value in iteritems(forwardable_headers):
            response[header] = value

        return self.middleware.process_response(
            self, self.request, result, response)