TreeWriter treeWriter = new TreeWriter(runtime);
treeWriter.startDocument(step.getNode().getBaseURI());
treeWriter.addStartElement(c_error);
treeWriter.addNamespace(cpfx, cns);
treeWriter.addAttribute(_name, step.getName());
treeWriter.addAttribute(_type, "p:error");
treeWriter.addAttribute(_code, errorCode.toString());
treeWriter.startContent();
if (doc != null) {
treeWriter.addSubtree(doc);