// Transaction support is optional for level 0 compliance
private void transactionalInsertDOMDocument(String id1, Document document1,
String id2, Document document2) throws Exception {
TransactionService transaction =
(TransactionService) col.getService("TransactionService", "1.0");
transaction.begin();
XMLResource resource1 =
(XMLResource) col.createResource(id1, XMLResource.RESOURCE_TYPE);
resource1.setContentAsDOM(document1);
col.storeResource(resource1);
XMLResource resource2 =
(XMLResource) col.createResource(id2, XMLResource.RESOURCE_TYPE);
resource2.setContentAsDOM(document2);
col.storeResource(resource2);
transaction.commit();
}