Upgrading model leads to existing data in old model being flushed

I had a simple model included in my ODL run (within a model.jar having artifact version 0.1.0-SNAPSHOT). The model was as follows:

module benchmarking {
namespace "urn:sdnhub:benchmarking";
prefix benchmarking;

description "This is a dummy model for benchmarking";

revision "2016-03-09"

{ description "initial version"; }

container dummy1 {
leaf data1

{ type uint32; }

}
}

I populated the data1 with an integer at runtime.

Then I generated a new model.jar with artifact version 0.2.0-SNAPSHOT and included the benchmarking.yang with revision-date "2016-03-10". I placed this model.jar in the deploy folder of karaf. The OSGi system picked it up and installed this. The model-0.1.0-SNAPSHOT.jar and model-0.2.0-SNAPSHOT.jar are both Active in OSGi.

After introducing the upgraded model, I noticed that the data in the old model was purged. This is unexpected. We need a way to preserve the current data in the old model so that the apps have an opportunity to port it over to the new model.