text: import time
  import os
  import binascii
  
  
  class UserIdGenerator(object):
      def __call__(self, instance):
          time_bits = '{:x}'.format(int(time.time() * 1e6))
          random_bits = binascii.hexlify(os.urandom(8)).decode()
          identifier = time_bits + random_bits
          return identifier
  
  user_id_generator = UserIdGenerator()
  
  __all__ = [
      user_id_generator
  ]