### Question:
LiteralExpressionUIModelMapper extends BaseUIModelMapper<LiteralExpression> { @Override public void toDMNModel(final int rowIndex, final int columnIndex, final Supplier<Optional<GridCellValue<?>>> cell) { dmnModel.get().ifPresent(literalExpression -> literalExpression.getText().setValue((String) cell.get().orElse(new BaseGridCellValue<>("")).getValue())); } LiteralExpressionUIModelMapper(final Supplier<GridData> uiModel,
                                          final Supplier<Optional<LiteralExpression>> dmnModel,
                                          final ListSelectorView.Presenter listSelector,
                                          final double lineHeight); @Override void fromDMNModel(final int rowIndex,
                             final int columnIndex); @Override void toDMNModel(final int rowIndex,
                           final int columnIndex,
                           final Supplier<Optional<GridCellValue<?>>> cell);  }### Answer:
@Test public void testToDmn_Null() { mapper.toDMNModel(0, 0, () -> Optional.of(new BaseGridCellValue<>(null))); assertNull(literalExpression.getText().getValue()); }
@Test public void testToDmn_Empty() { mapper.toDMNModel(0, 0, () -> Optional.of(new BaseGridCellValue<>(""))); assertEquals("", literalExpression.getText().getValue()); }
@Test public void testToDmn_MultiByte() { mapper.toDMNModel(0, 0, () -> Optional.of(new BaseGridCellValue<>("学校"))); assertEquals("学校", literalExpression.getText().getValue()); }