code: def select_renderer(self, request, renderers):
          
          if not len(request.accept_mimetypes):
              return renderers[0], renderers[0].mimetype
  
          for mimetype, quality in request.accept_mimetypes:
              accept_mimetype = MimeType.parse(mimetype)
              for renderer in renderers:
                  if accept_mimetype.match(renderer.mimetype):
                      return renderer, renderer.mimetype.replace(params=accept_mimetype.params)
  
          return None, None
docs: Selects the appropriated parser which matches to the request's accept.
          :param request: The HTTP request.
          :param renderers: The lists of parsers.
          :return: The parser selected or none.