import static org.mockito.Mockito.doReturn;
import static org.mockito.Mockito.mock;
-import com.google.common.base.Optional;
+import java.util.Optional;
import org.junit.Test;
import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidateNode;