import java.util.Optional;
import java.util.SortedSet;
import java.util.concurrent.TimeUnit;
-import javax.annotation.concurrent.GuardedBy;
+import org.checkerframework.checker.lock.qual.GuardedBy;
import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
import org.opendaylight.controller.cluster.datastore.utils.ActorUtils;
import org.slf4j.Logger;