testAddDragItemHoverClasses() {
    dlg.handleDragItemMouseover_(event);

    assertTrue(
        'Should have cursor_move class after MOUSEOVER',
        classlist.contains(event.currentTarget, 'cursor_move'));
    assertTrue(
        'Should have opacity_40 class after MOUSEOVER',
        classlist.contains(event.currentTarget, 'opacity_40'));
    assertFalse(
        'Should not have cursor_pointer class after MOUSEOVER',
        classlist.contains(event.currentTarget, 'cursor_pointer'));
    assertFalse(
        'Should not have blue_bg class after MOUSEOVER',
        classlist.contains(event.currentTarget, 'blue_bg'));
  }
Test the effect of hovering over a list.
Check that after the MOUSEOVER browser event these classes are added to
the current target of the event.
@suppress {visibility,checkTypes} suppression added to enable type checking