public void putDefaultNullValue(String fieldName, Object defaultNullValue) {
    _fieldToValueMap.put(fieldName, defaultNullValue);
    _nullValueFields.add(fieldName);
  }
@Test
  public void testNullValueFieldsEqual() {
    GenericRow first = new GenericRow();
    first.putDefaultNullValue("one", 1);
    GenericRow second = new GenericRow();
    second.putDefaultNullValue("one", 1);
    Assert.assertEquals(first, second);

    first = new GenericRow();
    first.putDefaultNullValue("one", null);
    second = new GenericRow();
    second.putDefaultNullValue("one", null);
    Assert.assertEquals(first, second);
  }