output.startElement("xsd:schema");
AttrImpl attr = new AttrImpl();
attr.addAttribute("name", ser.getXMLTypeName());
attr.addAttribute("type", ser.getXMLTypeName());
attr.addAttribute("nillable", "true");
output.startElement("xsd:element", attr);
output.endElement("xsd:element");
// get and document all used classes
_dependendClasses.add(type);