The code

—
enum NestingType {
NA, SINGLE, AS_COLLECTION;
}
—

seems unacceptable to Groovy 2.0.4 (bizarre...)

Error message:

Can't have an abstract method in a non-abstract class. The class must be declared abstract or the method 'int compareTo(Object)' must be implemented.

On the other hand, this may not be an actual problem -

See

http://forum.springsource.org/showthread.php?126928-Groovy-enum-issue-can-t-have-an-abstract-method-in-a-non-abstract-class

I will clean everything and see what's up.