def mergeRecordExtra(record, target, reserved):
    """ Merges extra attributes from LogRecord object into target dictionary
    
    Args:
        record (logging.LogRecord): logging.LogRecord
        target (dict): dict to update
        reserved (dict or list): reserved keys to skip
    
    Returns:
        dict: target dict
    """
    for key, value in record.__dict__.items():
        if key not in reserved and not (hasattr(key, 'startswith') and key.
            startswith('_')):
            target[key] = value
    return target
