### Question:
RuleAnnotationClauseColumnHeaderMetaData extends EditableTextHeaderMetaData<TextBox, TextBoxDOMElement> implements HasListSelectorControl,
                                                                                                                                HasCellEditorControls { @Override public List<ListSelectorItem> getItems(final int uiRowIndex, final int uiColumnIndex) { return listSelectorItemsSupplier.apply(uiRowIndex, uiColumnIndex); } RuleAnnotationClauseColumnHeaderMetaData(final Supplier<String> titleGetter,
                                                    final Consumer<String> titleSetter,
                                                    final SingletonDOMElementFactory<TextBox, TextBoxDOMElement> factory,
                                                    final Optional<String> placeHolder,
                                                    final BiFunction<Integer, Integer, List<ListSelectorItem>> listSelectorItemsSupplier,
                                                    final ListSelectorView.Presenter listSelector,
                                                    final Consumer<HasListSelectorControl.ListSelectorItem> listSelectorItemConsumer); @Override Optional<String> getPlaceHolder(); @Override Optional<Editor> getEditor(); @Override String getColumnGroup(); @Override List<ListSelectorItem> getItems(final int uiRowIndex,
                                           final int uiColumnIndex); @Override void onItemSelected(final ListSelectorItem item); @Override boolean equals(final Object o); @Override int hashCode(); static final String COLUMN_GROUP; }### Answer:
@Test public void testGetItems() { final int uiRowIndex = 5; final int uiColumnIndex = 6; final List<HasListSelectorControl.ListSelectorItem> expectedItems = mock(List.class); when(listSelectorItemsSupplier.apply(uiRowIndex, uiColumnIndex)).thenReturn(expectedItems); final List<HasListSelectorControl.ListSelectorItem> actualItems = column.getItems(uiRowIndex, uiColumnIndex); assertEquals(expectedItems, actualItems); verify(listSelectorItemsSupplier).apply(uiRowIndex, uiColumnIndex); }