### Question:
InvocationColumnExpressionHeaderMetaData extends EditableTextHeaderMetaData<TextBox, TextBoxDOMElement> implements HasCellEditorControls,
                                                                                                                                HasListSelectorControl { @Override public Group render(final GridHeaderColumnRenderContext context, final double blockWidth, final double blockHeight) { return RendererUtils.getExpressionHeaderText(this, context); } InvocationColumnExpressionHeaderMetaData(final Supplier<String> titleGetter,
                                                    final Consumer<String> titleSetter,
                                                    final SingletonDOMElementFactory<TextBox, TextBoxDOMElement> factory,
                                                    final Optional<String> placeHolder,
                                                    final ListSelectorView.Presenter listSelector,
                                                    final BiFunction<Integer, Integer, List<HasListSelectorControl.ListSelectorItem>> listSelectorItemsSupplier,
                                                    final Consumer<HasListSelectorControl.ListSelectorItem> listSelectorItemConsumer); @Override Group render(final GridHeaderColumnRenderContext context,
                        final double blockWidth,
                        final double blockHeight); @Override Optional<String> getPlaceHolder(); @Override Optional<Editor> getEditor(); @Override List<ListSelectorItem> getItems(final int uiRowIndex,
                                           final int uiColumnIndex); @Override void onItemSelected(final ListSelectorItem item);  }### Answer:
@Test public void testRender() { headerMetaData.render(context, BLOCK_WIDTH, BLOCK_HEIGHT); verify(textMock).setText(title); verify(textMock).setX(RendererUtils.EXPRESSION_TEXT_PADDING); verify(textMock).setY(RendererUtils.EXPRESSION_TEXT_PADDING); verify(textMock).setTextAlign(TextAlign.LEFT); }