code: def generic_http_header_parser_for(header_name):
      
  
      def parser():
          request_id = request.headers.get(header_name, '').strip()
  
          if not request_id:
              # If the request id is empty return None
              return None
          return request_id
      return parser
docs: A parser factory to extract the request id from an HTTP header
      :return: A parser that can be used to extract the request id from the current request context
      :rtype: ()->str|None