def format_success(event_dict=None):
    """
    Creates or updates an event dict to include the standard 'error' and 'has_error' fields with default values

    Args:
        event_dict (dict): Optional input to pass a dict of existing results to update. If none is provided, a dict
            containing only the new default fields will be returned.

    Returns:
        dict: New or updated dict containing default 'error' and 'has_error' keys
    """
    if not isinstance(event_dict, dict):
        event_dict = {'result': event_dict}
    event_dict.update({'error': None, 'has_error': False})
    return event_dict
