def clean_filters(filters: Mapping = None) -> str:
    """
    Checks the values inside `filters`
    https://docs.docker.com/engine/api/v1.29/#operation/ServiceList
    Returns a new dictionary in the format `map[string][]string` jsonized
    """

    if filters and isinstance(filters, dict):
        for k, v in filters.items():
            if not isinstance(v, list):
                v = [v]
            filters[k] = v

    return json.dumps(filters)