What the Serializable!? #WTS

SerializableLambda.md

As stated by Oracle,

You can serialize a lambda expression if its target type and its captured arguments are serializable. However, like inner classes, the serialization of lambda expressions is strongly discouraged.

Interesting that the following works:

import java.util.Optional;

public class Test {

    public static void main(String[] args) {

        Optional<Object> opt = Optional.of(new Object());

        Function0<Optional<Object>> f = Function0.lift(() -> opt);

        // = "java.util.Optional"
        System.out.println(f.getType().returnType().getName());

        // = "(Ljava/util/Optional;)Ljava/util/Optional;"
        System.out.println(λ.getSerializedLambda(f).getImplMethodSignature());

    }
}

We see that Optional is a captured lambda argument and we know that it is not Serializable.

Is this good or bad?