XStep step = runtime.runningStep();
if (step != null && step.getNode() != null) {
XdmNode node = step.getNode();
if (node.getBaseURI() != null) {
treeWriter.addAttribute(_href, node.getBaseURI().toString());
}
if (node.getLineNumber() > 0) {
treeWriter.addAttribute(_line, ""+node.getLineNumber());
}
if (node.getColumnNumber() > 0) {