import static org.junit.Assert.assertEquals;
import akka.actor.ActorRef;
-import com.google.common.base.Optional;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Sets;
import java.util.Arrays;
+import java.util.Optional;
import java.util.concurrent.TimeUnit;
import org.junit.Test;
import org.opendaylight.controller.cluster.notifications.LeaderStateChanged;