public boolean processStartElement(XdmNode node) {
// Use a TreeWriter to make the matching node into a proper document
TreeWriter treeWriter = new TreeWriter(runtime);
treeWriter.startDocument(node.getBaseURI());
treeWriter.addSubtree(node);
treeWriter.endDocument();
current.resetWriter();
current.write(treeWriter.getResult());
logger.trace(MessageFormatter.nodeMessage(step.getNode(), "Viewport copy matching node to " + current));