// Small client program of our collections
public class CollectionsClient {
	public static void main(String[] args) {
		System.out.println("Hello world!");
		
		List<Integer> list = new ArrayList<Integer>();
		list.add(1);
		list.add(2);
		System.out.println(sum(list));
		
		System.out.println(sum(new LinkedList<Integer>()));
		
		// Also implements Queue interface!
		Queue<Integer> q = new LinkedList<Integer>();
	}
	
	public static int sum(List<Integer> list) {
		int sum = 0;
		for (int i = 0; i < list.size(); i++) {
			sum += list.get(i);
		}
		return sum;
	}

}