java.lang.IllegalStateException: Unsupported DOM Modification type UNMODIFIED

I am seeing this exception happen in Lithium. This happens when I getModifiedChildren on a DataObjectModification and call getModificationType on one of the modified children. Why would this happen?

2016-03-05 00:15:12.844 GMT+00:00 [opendaylight-cluster-data-notification-dispatcher-54] ERROR o.o.c.c.d.DataTreeChangeListenerActor - Error notifying listener org.opendaylight.controller.md.sal.binding.impl.BindingClusteredDOMDataTreeChangeListenerAdapter@79048d7e
java.lang.IllegalStateException: Unsupported DOM Modification type UNMODIFIED
at org.opendaylight.controller.md.sal.binding.impl.LazyDataObjectModification.getModificationType(LazyDataObjectModification.java:150) [na:na]
at com.cisco.osc.application.MyListener.onDataTreeChanged(MyListener.java:106) [com.cisco.osc.application.my-provider:0.1.2.Lithium-SR2-00003-1000]
at org.opendaylight.controller.md.sal.binding.impl.BindingDOMDataTreeChangeListenerAdapter.onDataTreeChanged(BindingDOMDataTreeChangeListenerAdapter.java:41) [na:na]
at org.opendaylight.controller.cluster.datastore.DataTreeChangeListenerActor.dataChanged(DataTreeChangeListenerActor.java:53) [org.opendaylight.controller.sal-distributed-datastore:1.2.2.Lithium-SR2-00003-865]
at org.opendaylight.controller.cluster.datastore.DataTreeChangeListenerActor.handleReceive(DataTreeChangeListenerActor.java:37) [org.opendaylight.controller.sal-distributed-datastore:1.2.2.Lithium-SR2-00003-865]
at org.opendaylight.controller.cluster.common.actor.AbstractUntypedActor.onReceive(AbstractUntypedActor.java:34) [org.opendaylight.controller.sal-clustering-commons:1.2.2.Lithium-SR2-00003-865]
at akka.actor.UntypedActor$$anonfun$receive$1.applyOrElse(UntypedActor.scala:167) [com.typesafe.akka.actor:2.3.10]
at akka.actor.Actor$class.aroundReceive(Actor.scala:467) [com.typesafe.akka.actor:2.3.10]
at akka.actor.UntypedActor.aroundReceive(UntypedActor.scala:97) [com.typesafe.akka.actor:2.3.10]
at akka.actor.ActorCell.receiveMessage(ActorCell.scala:516) [com.typesafe.akka.actor:2.3.10]
at akka.actor.ActorCell.invoke(ActorCell.scala:487) [com.typesafe.akka.actor:2.3.10]
at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:254) [com.typesafe.akka.actor:2.3.10]
at akka.dispatch.Mailbox.run(Mailbox.scala:221) [com.typesafe.akka.actor:2.3.10]
at akka.dispatch.Mailbox.exec(Mailbox.scala:231) [com.typesafe.akka.actor:2.3.10]
at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260) [org.scala-lang.scala-library:2.10.4.v20140209-180020-VFINAL-b66a39653b]
at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339) [org.scala-lang.scala-library:2.10.4.v20140209-180020-VFINAL-b66a39653b]
at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979) [org.scala-lang.scala-library:2.10.4.v20140209-180020-VFINAL-b66a39653b]
at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107) [org.scala-lang.scala-library:2.10.4.v20140209-180020-VFINAL-b66a39653b]