fix: cannot assign Native to property of type Closure

[calebdw]

Hello!

When an object is serialized, all of its properties are recursively walked using reflection to wrap any closures. However, when an object has a property that's typed as Closure this causes a TypeError to be thrown (cannot assign Native to property of type Closure)---even on objects that implement __serialize and explicitly handle the closure.

The fix is to simply check if an object implements __serialize and if so, defer to that method for serialization instead of trying to still walk its properties.

Thanks!

[calebdw]

Thanks!