public void putValue(String fieldName, @Nullable Object value) {
    _fieldToValueMap.put(fieldName, value);
  }
@Test
  public void testDifferentNumberOfKeysWithNoSameValueNotEqual() {
    GenericRow first = new GenericRow();
    first.putValue("one", 1);
    first.putValue("two", 2);
    GenericRow second = new GenericRow();
    second.putValue("one", "one");
    Assert.assertNotEquals(first, second);
  }