public void testIteratorSet() throws CloneNotSupportedException {
   Vector clone = test.clone();
   Iterator<Vector.Element> it = clone.iterateNonZero();
   while (it.hasNext()) {
     Vector.Element e = it.next();
     e.set(e.get() * 2.0);
   }
   it = clone.iterateNonZero();
   while (it.hasNext()) {
     Vector.Element e = it.next();
     assertEquals(test.get(e.index()) * 2.0, e.get());
   }
   clone = test.clone();
   it = clone.iterator();
   while (it.hasNext()) {
     Vector.Element e = it.next();
     e.set(e.get() * 2.0);
   }
   it = clone.iterator();
   while (it.hasNext()) {
     Vector.Element e = it.next();
     assertEquals(test.get(e.index()) * 2.0, e.get());
   }
 }