How to Create Category Values using REST and JAXB

I'm trying to create category values using RQM REST and the JAXB classes generated from the QM schemas.  From examining the XML content of the  /category and /categoryType feeds:

1.  What the qm UI calls a category is  CategoryType (JAXB class)
2.  What the qm UI calls a category value is a Category (JAXB class)
3.  A Category is associated with a CategoryType.

I'm able to create categories by POSTing CategoryType objects:
CategoryType catType = new CategoryType();
catType.setTitle("Country");
catType.setProjectArea(projectArea);
catType.setScope("TestPlan");
catType.setRequired(false);
catType.setMultiSelectable(false);

I'm dead in the water trying to create and associate values, i.e., create and associate a Category with a CategoryType. 

As far as I can tell, you make the association by invoking setCategoryType() on the Category.  The challenge is that the argument to setCategoryType()  needs to be a Category.CategoryType -- not the CategoryType used to create the CategoryType.