WithVKey

```
@Target(TYPE)
public @interface WithVKey
```
Annotation for Entity that can be saved as a foreign key in the form of a VKey in another table.
A AttributeConverter named VKeyConverter_[EntityClassSimpleName] will be automatically generated by google.registry.processors.VKeyProcessor, this class must be manually added to persistence.xml in order for it to be picked up by Hibernate.

- Required Element Summary
  
  Required Elements
  Modifier and Type Required Element Description
  
  java.lang.Class<? extends java.io.Serializable> value
  The type of the SQL primary ID of the entity that is saved in the VKey

- Element Detail
  - value
```
java.lang.Class<? extends java.io.Serializable> value
```
    The type of the SQL primary ID of the entity that is saved in the VKey