public class AsExternalTypeSerializer extends TypeSerializerBase
Type serializer that preferably embeds type information as an "external" type property; embedded in enclosing JSON object. Note that this serializer should only be used when value is being output at JSON Object context; otherwise it cannot work reliably, and will have to revert operation similar to AsPropertyTypeSerializer.

Note that implementation of serialization is bit cumbersome as we must serialized external type id AFTER object; this because callback only occurs after field name has been written.

Also note that this type of type id inclusion will NOT try to make use of native Type Ids, even if those exist.