Performance issue in SetUtils::isEqualSet

    /**
     * Tests two sets for equality as per the <code>equals()</code> contract
     * in {@link java.util.Set#equals(java.lang.Object)}.
     * <p>
     * This method is useful for implementing <code>Set</code> when you cannot
     * extend AbstractSet. The method takes Collection instances to enable other
     * collection types to use the Set implementation algorithm.
     * <p>
     * The relevant text (slightly paraphrased as this is a static method) is:
     * <blockquote>
     * <p>Two sets are considered equal if they have
     * the same size, and every member of the first set is contained in
     * the second. This ensures that the <tt>equals</tt> method works
     * properly across different implementations of the <tt>Set</tt>
     * interface.</p>
     *
     * <p>
     * This implementation first checks if the two sets are the same object:
     * if so it returns <tt>true</tt>.  Then, it checks if the two sets are
     * identical in size; if not, it returns false. If so, it returns
     * <tt>a.containsAll((Collection) b)</tt>.</p>
     * </blockquote>
     *
     * @see java.util.Set
     * @param set1  the first set, may be null
     * @param set2  the second set, may be null
     * @return whether the sets are equal by value comparison
     */
    public static boolean isEqualSet(final Collection<?> set1, final Collection<?> set2) {
        if (set1 == set2) {
            return true;
        }
        if (set1 == null || set2 == null || set1.size() != set2.size()) {
            return false;
        }

        return set1.containsAll(set2);
    }

    public static void 	setUtilsisEqualSetTest(boolean original) {

	int N=500000;
	ArrayList<Integer> firstArrayList=new ArrayList<Integer>();
	ArrayList<Integer> secondArrayList=new ArrayList<Integer>();
	for(int i=0;i<N;++i) {

	    firstArrayList.add(new Integer(i));
	    secondArrayList.add(new Integer((N-1)-i));
	    
	}

	SetUtils.isEqualSet(original?firstArrayList:(new HashSet<Integer>(firstArrayList)),secondArrayList);