*/
package org.opendaylight.controller.md.sal.dom.store.impl;
-import com.google.common.base.Optional;
import java.util.Collection;
import java.util.Collections;
+import java.util.Optional;
import java.util.concurrent.ExecutorService;
import javax.annotation.Nonnull;
import org.opendaylight.controller.md.sal.dom.api.DOMDataTreeChangeListener;