### Question:
LiteralExpressionPMMLColumn extends DMNSimpleGridColumn<LiteralExpressionPMMLGrid, String> implements HasSingletonDOMElementResource { @Override public void edit(final GridCell<String> cell, final GridBodyCellRenderContext context, final Consumer<GridCellValue<String>> callback) { gridWidget.loadValues(doEdit(cell, context)); } LiteralExpressionPMMLColumn(final ListBoxSingletonDOMElementFactory factory,
                                       final double width,
                                       final LiteralExpressionPMMLGrid gridWidget); @Override void edit(final GridCell<String> cell,
                     final GridBodyCellRenderContext context,
                     final Consumer<GridCellValue<String>> callback); @Override void flush(); @Override void destroyResources(); @Override void setWidth(final double width);  }### Answer:
@Test @SuppressWarnings("unchecked") public void testListBoxInitialisation() { final GridCell<String> cell = new BaseGridCell<>(new BaseGridCellValue<>(LISTBOX_ENTRY1)); column.edit(cell, context, result -> {}); assertCellEdit(LISTBOX_ENTRY1); verify(widget).clear(); verify(widget).addItem(LISTBOX_ENTRY1, "\"" + LISTBOX_ENTRY1 + "\""); verify(widget).addItem(LISTBOX_ENTRY2, "\"" + LISTBOX_ENTRY2 + "\""); }