// Create an instance of the sample to test.
SubstitutionGroup sample = new SubstitutionGroup();
// Create a schema type instance from the XML indicated by the path.
SubstitutionGroup subGrp = new SubstitutionGroup();
PurchaseOrderDocument poDoc = subGrp.parseXml(args[0]);
// Validate the XML.
assert sample.validateXml(poDoc);
// Create a new document that adds two elements.
PurchaseOrderDocument newDoc = sample.createDocument(poDoc, args[1]);
// Validate the XML.
assert sample.validateXml(newDoc);
}