code: def split(nonce_string):
      
      timestamp_str = nonce_string[:time_str_len]
      try:
          timestamp = timegm(strptime(timestamp_str, time_fmt))
      except AssertionError: # Python 2.2
          timestamp = -1
      if timestamp < 0:
          raise ValueError('time out of range')
      return timestamp, nonce_string[time_str_len:]
docs: Extract a timestamp from the given nonce string
  
      @param nonce_string: the nonce from which to extract the timestamp
      @type nonce_string: str
  
      @returns: A pair of a Unix timestamp and the salt characters
      @returntype: (int, str)
  
      @raises ValueError: if the nonce does not start with a correctly
          formatted time string