UserGroupsExplorer implements IsWidget { public void clear() { view.clear(); canRemove = false; } @Inject  UserGroupsExplorer(GroupsList groupList,
                              View view,
                              ConfirmBox confirmBox,
                              Event<RemoveUserGroupEvent> removeUserGroupEventEvent); @Override Widget asWidget(); @PostConstruct void init(); void show(final Set<Group> groups,
                     final boolean canRemove); void clear();  }
@Test public void testClear() throws Exception { presenter.clear(); assertFalse(presenter.canRemove); verify(view, times(1)).clear(); }