.addEqualityGroup(Predicates.equalTo("null"))
        .testEquals();
  }

  @J2ktIncompatible
  @GwtIncompatible // SerializableTester
  public void testIsEqualToNull_serialization() {
    checkSerialization(Predicates.equalTo(null));
  }

  /**
   * Tests for Predicates.instanceOf(x). TODO: Fix the comment style after fixing annotation