@Test
  public void testEqualsWithNullable() throws Exception {
    NullableNonNullable everythingNull =
        NullableNonNullable.create(null, null, "nonNullableString");
    NullableNonNullable somethingNull =
        NullableNonNullable.create(null, "otherNullableString", "nonNullableString");
    NullableNonNullable nothingNull =
        NullableNonNullable.create("nullableString", "otherNullableString", "nonNullableString");
    NullableNonNullable nothingNullAgain =
        NullableNonNullable.create("nullableString", "otherNullableString", "nonNullableString");
    new EqualsTester()
        .addEqualityGroup(everythingNull)
        .addEqualityGroup(somethingNull)
        .addEqualityGroup(nothingNull, nothingNullAgain)
        .testEquals();
  }
Returns a set containing this test's {@link Nullable @Nullable} annotation, plus possibly
another {@code @Nullable} that is present on the parameter of {@link Object#equals}.
value/src/it/functional/src/test/java/com/google/auto/value/AutoValueJava8Test.java