protected ClassDescriptor buildClassDescriptorDescriptor() {
XMLDescriptor descriptor = new XMLDescriptor();
descriptor.setJavaClass(ClassDescriptor.class);
descriptor.setDefaultRootElement("class-mapping-descriptor");
descriptor.getInheritancePolicy().setClassIndicatorField(new XMLField("@xsi:type"));
descriptor.getInheritancePolicy().addClassIndicator(ClassDescriptor.class, getPrimaryNamespaceXPath() + "relational-class-mapping-descriptor");
descriptor.getInheritancePolicy().addClassIndicator(RelationalDescriptor.class, getPrimaryNamespaceXPath() + "relational-class-mapping-descriptor");
descriptor.getInheritancePolicy().addClassIndicator(ObjectRelationalDataTypeDescriptor.class, getPrimaryNamespaceXPath() + "object-relational-class-mapping-descriptor");
descriptor.getInheritancePolicy().addClassIndicator(EISDescriptor.class, getPrimaryNamespaceXPath() + "eis-class-mapping-descriptor");
descriptor.getInheritancePolicy().addClassIndicator(XMLDescriptor.class, getPrimaryNamespaceXPath() + "xml-class-mapping-descriptor");