The getRef()
task needs to be implemented in your Type.
This method is responsible for returning a referenced object; it needs to check
to make sure the referenced object is of the correct type (i.e. you can't try to
refer to a RegularExpresson from a DSN DataType) and that the reference is not
circular.
You can probably just copy this method from an existing Type and make the few changes that customize it to your Type.