### Question:
InvocationGrid extends BaseExpressionGrid<Invocation, InvocationGridData, InvocationUIModelMapper> implements HasListSelectorControl { @SuppressWarnings("unused") List<ListSelectorItem> getHeaderItems(final int uiHeaderRowIndex, final int uiHeaderColumnIndex) { final List<ListSelectorItem> items = new ArrayList<>(); items.add(ListSelectorHeaderItem.build(translationService.format(DMNEditorConstants.InvocationEditor_Header))); items.add(ListSelectorTextItem.build(translationService.format(DMNEditorConstants.InvocationEditor_InsertParameter), true, () -> { cellEditorControls.hide(); getExpression().get().ifPresent(e -> addParameterBinding(model.getRowCount())); })); return items; } InvocationGrid(final GridCellTuple parent,
                          final Optional<String> nodeUUID,
                          final HasExpression hasExpression,
                          final Optional<HasName> hasName,
                          final DMNGridPanel gridPanel,
                          final DMNGridLayer gridLayer,
                          final InvocationGridData gridData,
                          final DefinitionUtils definitionUtils,
                          final SessionManager sessionManager,
                          final SessionCommandManager<AbstractCanvasHandler> sessionCommandManager,
                          final DefaultCanvasCommandFactory canvasCommandFactory,
                          final Event<ExpressionEditorChanged> editorSelectedEvent,
                          final Event<RefreshFormPropertiesEvent> refreshFormPropertiesEvent,
                          final Event<DomainObjectSelectionEvent> domainObjectSelectionEvent,
                          final CellEditorControlsView.Presenter cellEditorControls,
                          final ListSelectorView.Presenter listSelector,
                          final TranslationService translationService,
                          final boolean isOnlyVisualChangeAllowed,
                          final int nesting,
                          final Supplier<ExpressionEditorDefinitions> expressionEditorDefinitionsSupplier,
                          final ValueAndDataTypePopoverView.Presenter headerEditor,
                          final ReadOnlyProvider readOnlyProvider); @Override InvocationUIModelMapper makeUiModelMapper(); @Override void initialiseUiRows(); @Override void initialiseUiCells(); @Override @SuppressWarnings("unused") List<ListSelectorItem> getItems(final int uiRowIndex,
                                           final int uiColumnIndex); @Override void onItemSelected(final ListSelectorItem item); @Override void doAfterSelectionChange(final int uiRowIndex,
                                       final int uiColumnIndex); @Override void doAfterHeaderSelectionChange(final int uiHeaderRowIndex,
                                             final int uiHeaderColumnIndex);  }### Answer:
@Test public void testGetHeaderItemsRowNumberColumn() { setupGrid(0); assertDefaultHeaderListItems(grid.getHeaderItems(0, 0)); }
@Test public void testGetHeaderItemsNameColumn() { setupGrid(0); assertDefaultHeaderListItems(grid.getHeaderItems(0, 1)); }
@Test public void testGetHeaderItemsExpressionColumn() { setupGrid(0); assertDefaultHeaderListItems(grid.getHeaderItems(0, 2)); }