JAXBParser parser = newJAXBParser();
InputSource isource = new InputSource(new StringReader(schemaSource));
isource.setSystemId("testPurchaseOrder.xsd");
JAXBSchema schema = (JAXBSchema) parser.parse(isource);
JAXBGlobalBindings globalBindings = schema.getJAXBGlobalBindings();
assertNotNull(globalBindings);
XSType[] schemaTypes = schema.getTypes();
assertNotNull(schemaTypes);
assertEquals(4, schemaTypes.length);