@Test
public void testNewDivider() {

    navTreeEditor.setOnUpdateCommand(updateCommand);
    navTreeEditor.edit(NAV_TREE);
    navTreeEditor.collapse();
    assertFalse(navTreeEditor.isExpanded());
    reset(view);
    navTreeEditor.newDivider();
    assertTrue(navTreeEditor.isExpanded());
    assertEquals(((NavGroup) navTreeEditor.getNavItem()).getChildren().size(), 3);
    verify(view, times(3)).addChild(any());
    verify(updateCommand).execute();
}