Generic Find Duplicates - java

/**
     *
     * @param list The list to be checked for duplicates
     * @param <T>
     * @return A TreeMap with only one item. The key of the Map is a Boolean that indicates whether dublicates exists or not. The value is a HashSet of the duplicate values.
     */
    public static <T> TreeMap<Boolean,Set<T>> findDuplicates(Collection<T> list) {

        Set<T> duplicates = new HashSet<T>();
        Set<T> uniques = new HashSet<T>();
        TreeMap<Boolean,Set<T>> map = new TreeMap();

        for(T t : list) {
            if(!uniques.add(t)) {
                duplicates.add(t);
            }
        }
        Boolean foundDublicates = false;
        if (duplicates.size() > 0){
            foundDublicates = true;
        }
        map.put(foundDublicates,duplicates);
        return map;
    }