'Processes request to validate app version that is making request.
Returns:
Http response with status code 426 (i.e. Update Required) if request is from
mobile native app and app version is no longer supported else returns None'

def process_request(self, request):

    version_data = self._get_version_info(request)
    if version_data:
        last_supported_date = version_data[self.LAST_SUPPORTED_DATE_HEADER]
        if (last_supported_date != self.NO_LAST_SUPPORTED_DATE):
            if (datetime.now().replace(tzinfo=UTC) > last_supported_date):
                return HttpResponse(status=426)
