Cannot create an enum attribute on an Entity

I've created a Language enum (with java-new-enum) and then I want my entity Book to have an attribute of type Language. In Forge 1.x I would do :

field custom --named language --type org.javaone.javaee7.model.Language.java ;

There is no such custom attribute in Forge 2.x and the following doesn't work :

jpa-new-field --named language --typeName org.javaone.javaee7.model.Language.java ;