ITERATIONS AND ITERATORS - MAKING YOUR OWN - SOMETIMES YOU CAN JUST DELEGATE
import java.util.ArrayList;
import java.util.Iterator;
class TestHolder {
   private ArrayList<Test> list = new ArrayList<Test>();
   public void add(Test t) { list.add(t); }
   public Iterator iterator() { return list.iterator(); }
}
class Test {
  private String name;
  public Test(String name) { this.name = name; }
  public String getName() { return name; }
  public static void main(String[] args) {
      TestHolder th = new TestHolder();
      th.add(new Test("hi")); th.add(new Test("there"));
     for (Iterator i = th.iterator(); i.hasNext(); ) {
        Test t = (Test) i.next();
        System.out.println(t.getName());
     } } }
$ javac Test.java;java Test
hi
there
$