TreeWriter tree = new TreeWriter(runtime);
tree.startDocument(doc.getBaseURI());
for (XdmNode child : new AxisNodes(doc, Axis.CHILD)) {
if (child.getNodeKind() == XdmNodeKind.COMMENT) {
tree.addComment(child.getStringValue());
} else if (child.getNodeKind() == XdmNodeKind.PROCESSING_INSTRUCTION) {
tree.addPI(child.getNodeName().getLocalName(), child.getStringValue());
} else if (child.getNodeKind() == XdmNodeKind.TEXT) {
tree.addText(child.getStringValue());
} else {