-import static com.google.common.base.Preconditions.checkNotNull;
-import static com.google.common.base.Preconditions.checkState;
-import static java.lang.String.format;
-import static org.opendaylight.controller.config.yangjmxgenerator.ConfigConstants.createConfigQName;
-
+import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.Optional;
+import com.google.common.collect.Sets;