code: public void simpleFastWrite(Writer out)
              throws IOException, XmlModelWriterException
      {
          out.write("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n");
          
          if (_publicID != null && _systemID != null) {
              out.write("<!DOCTYPE ");
              out.write(_rootName);
              out.write(" PUBLIC \"");
              out.write(_publicID);
              out.write("\" \"");
              out.write(_systemID);
              out.write("\">\n");
          }
          
          writeElement(out, _doc.getDocumentElement(), 0);
      }
docs: Write the XML to a stream, without using standard APIs.  This appears to be about ten times as fast (for our
  simple purposes) as using a Transformer ({@link #write}), and it avoids JDK and environment issues with obtaining
  a TransformerFactory.