private boolean containsInstanceof(Class<?extends GameObject> cls) {
    return this.getFirst() instanceof cls || this.getSecond() instanceof cls;
}

private boolean containsInstanceof(Class<?extends GameObject> cls) {
    return this.getFirst().getClass().getName().equals(cls.getName()) ||
           this.getSecond().getClass().getName().equals(cls.getName());
}

cls.isInstance(this.getFirst())