def add_to_set(entries, new):
    """Adds an entry to a list and makes a set for uniqueness before returning the list.

    Args:
        entries: `list`.
        new: (any datatype) The new member to add to the list.

    Returns:
        `list`: A deduplicated list.
    """
    entries.append(new)
    unique_list = list(set(entries))
    return unique_list