public void putValue(String fieldName, @Nullable Object value) {
    _fieldToValueMap.put(fieldName, value);
  }
@Test
  public void testMapValuesDifferentSizeNotEqual() {
    GenericRow first = new GenericRow();
    first.putValue("one", 1);
    HashMap<String, Object> firstData = new HashMap<String, Object>();
    firstData.put("two", 2);
    firstData.put("three", 3);

    GenericRow second = new GenericRow();
    HashMap<String, Object> secondData = new HashMap<String, Object>();
    secondData.put("two", 2);
    second.putValue("one", secondData);

    Assert.assertNotEquals(first, second);
  }