public void testClone() {
v1=new Vector();
v1.addElement(a1);
v1.addElement(a2);
v1.addElement(a3);
m2=new Membership(v1);
m1=(Membership)m2.clone();
assertEquals(m1.size(), m2.size());
assertTrue(m1.contains(a1));
assertTrue(m1.contains(a2));
assertTrue(m2.contains(a1));