code: def metadata(request, config_loader_path=None, valid_for=None):
      
      conf = get_config(config_loader_path, request)
      metadata = entity_descriptor(conf)
      return HttpResponse(content=text_type(metadata).encode('utf-8'),
                          content_type="text/xml; charset=utf8")
docs: Returns an XML with the SAML 2.0 metadata for this
      SP as configured in the settings.py file.