private List<Integer> findSharedMovies(int user1, int user2) {
		List<Integer> sharedMovies = new ArrayList<Integer>();
		HashSet<Integer> user1Movies = userRatedMovies.get(user1);
		HashSet<Integer> user2Movies = userRatedMovies.get(user2);
		if (user1Movies == null || user2Movies == null) {
			return sharedMovies;
		}
		Iterator<Integer> it = user1Movies.iterator();
		while (it.hasNext()) {
			Integer value = (Integer) it.next();
			if (user2Movies.contains(value)) {
				sharedMovies.add(value);
			}
		}
		return sharedMovies;
	}