[Libvirt-cim] How does libvirt-CIM

The web page advertises that libvirt-CIM is based on the CIM 2.16 schema. As we look at the latest libvirt-CIM in the HG repository there are a number of classes that are not in the 2.16 schema but show up in later schemas (2.19.1 and 2.20 experimental), for example CIM_VirtualSystemMigrationCapabilities class. Can you help me understand what the strategy is relative to the use/implementation of classes not part of the 2.16 schema but now part of current schema? Are there plans to re-base to a newer version of the CIM schema? Thanks. Dayne Medlyn