def _list_remove_duplicates(list_with_dup):
    """
    Return a copy of a list without duplicated items.

    :param list_with_dup: Input list that may contain duplicates
    :return: List that does not contain duplicates
    """
    set_no_dup = set(list_with_dup)
    list_no_dup = list(set_no_dup)
    return list_no_dup