code: def http_persistent (response):
      
      headers = response.getheaders()
      if response.version == 11:
          return not has_header_value(headers, 'Connection', 'Close')
      return has_header_value(headers, "Connection", "Keep-Alive")
docs: See if the HTTP connection can be kept open according the the
      header values found in the response object.
  
      @param response: response instance
      @type response: httplib.HTTPResponse
      @return: True if connection is persistent
      @rtype: bool