@Override
@Test
public void shouldCorrectlyWriteSimpleBsonObjectWithNullValue() {

    writer = new PrettyJsonWriter();
    BasicDocument top = new BasicDocument();
    top.put("firstName", "Jack");
    top.put("lastName", null);
    top.put("age", 31);
    String actual = writer.write(top);
    String expected = "{\n  \"firstName\" : \"Jack\",\n  \"lastName\" : null,\n  \"age\" : 31\n}";
    assertSame(expected, actual);
}