get_unlock_retries
Description:
Gets a UnlockRetries object, which provides, for each MMModemLock handled by the modem, the number of PIN tries remaining before the code becomes blocked (requiring a PUK) or permanently blocked.
Warning: 
      
        
    
    The values reported by this are not updated when the values in the interface change. Instead, the client is expected to call get_unlock_retries again to get a new UnlockRetries with the new values.
Parameters:
| this | A Modem. | 
Returns:
| A UnlockRetries that must be freed with 
            unref or  |