-import com.google.common.base.Optional;
-import org.opendaylight.controller.config.persist.api.storage.StorageAdapter;
+import java.io.IOException;
+import java.util.Collections;
+import java.util.List;
+import org.opendaylight.controller.config.persist.api.ConfigSnapshotHolder;
+import org.opendaylight.controller.config.persist.api.Persister;
+import org.opendaylight.controller.config.persist.api.PropertiesProvider;
+import org.opendaylight.controller.config.persist.api.StorageAdapter;