}
    }

    private static Nullability nullabilityOf(CtBehavior behavior) {
        NullableMethodVisitor visitor = new NullableMethodVisitor(behavior)
        new ClassReader(byteCodeFrom(behavior.getDeclaringClass())).accept(visitor, 0)
        return visitor.nullability
    }

    static class NullableMethodVisitor extends ClassVisitor {
        Nullability nullability = Nullability.NON_NULL