m.addListDataListener(this);
harness.check(m.getSize(), 3);
harness.check(m.getSelectedItem(), "A");
m.removeAllElements();
harness.check(m.getSize(), 0);
harness.check(m.getSelectedItem(), null);
harness.check(eventType, ListDataEvent.INTERVAL_REMOVED);
harness.check(index0, 0);
harness.check(index1, 2);