@Test
public void nullElements() {

    List<ResultElement> row = new ArrayList<ResultElement>();
    row.add(null);
    row.add(null);
    row.add(null);
    row.add(null);
    List<List<ResultElement>> table = Arrays.asList(row);
    MemoryOutput output = new MemoryOutput();
    ResultProcessor processor = new ResultProcessor();
    processor.write(table.iterator(), output);
    assertEquals("Every null element should now be an empty string",
            Arrays.asList("", "", "", ""),
            output.getResults().get(0));
}