### Question:
UndefinedExpressionCell extends DMNGridCell<String> { @Override public Optional<Editor> getEditor() { return Optional.of(listSelector); } UndefinedExpressionCell(final ListSelectorView.Presenter listSelector,
                                   final TranslationService translationService); @Override Optional<Editor> getEditor(); @Override GridCellEditAction getSupportedEditAction();  }### Answer:
@Test public void testGetEditor() { assertThat(cell.getEditor()).isNotEmpty(); assertThat(cell.getEditor().get()).isSameAs(listSelector); }