new_contents: #!/usr/bin/env python3
  
  """Test data transmit of random strings between bridges nodes.
  
  use USB Null Modem Cable between /dev/ttyUSB0 and /dev/ttyUSB1
  on node0: ./redis-serial-sync --remote node1 --db 0 /dev/ttyUSB0
  on node1: ./redis-serial-sync --remote node0 --db 1 /dev/ttyUSB1
  """
  
  import atexit
  import time
  import string
  import random
  import secrets
  import uuid
  import redis
  
  # some const
  CHARS_BUNDLE = string.ascii_letters + string.digits + string.punctuation
  
  
  if __name__ == '__main__':
      db0 = redis.StrictRedis(db=0)
      db1 = redis.StrictRedis(db=1)
      your_uuid = uuid.uuid4()
      tx_key = f'tx:node1:test-{your_uuid}'
      rx_key = f'rx:node0:test-{your_uuid}'
      good_count = 0
      # clean db1 at exit
      atexit.register(db1.delete, rx_key)
  
      while True:
          # get a random string from bundle char src
          rand_str = ''.join(secrets.choice(CHARS_BUNDLE) for i in range(random.randint(64, 4096)))
          # send tx random bytes
          tx_rand_bytes = rand_str.encode()
          db0.set(tx_key, tx_rand_bytes)
          # wait for transmit node0 -> serial -> node1
          time.sleep(0.5)
          # receive rx random bytes
          rx_rand_bytes = db1.get(rx_key)
          # print test result
          if rx_rand_bytes != tx_rand_bytes:
              print('-' * 80)
              print('MISMATCH DETECT')
              print(f'{tx_key} is {tx_rand_bytes}')
              print(f'{rx_key} is {rx_rand_bytes}')
              good_count = 0
          else:
              if not good_count % 80:
                  print('')
              print('.', end='', flush=True)
              good_count += 1
  
subject: add utils/