Clean all messages

Clean all messages in message workspace

import javax.jcr.Node;
import info.magnolia.jcr.predicate.NodeTypePredicate;

Node rootNode =  SessionUtil.getNode("messages", "/");
Iterable<Node> nodeList = NodeUtil.collectAllChildren(rootNode, new NodeTypePredicate("mgnl:systemMessage"));

for (Node node : nodeList) {
    println node.getPath();
    node.remove()
}

rootNode.save()
return "messages killed"