private void deleteTutorial() {
// Delete object examples
Expression qualifier = ExpressionFactory.matchExp(Artist.NAME_KEY,
"Pablo Picasso");
SelectQuery selectToDelete = new SelectQuery(Artist.class, qualifier);
Artist picasso = (Artist) Cayenne.objectForQuery(objContext,
selectToDelete);
if (picasso != null) {
objContext.deleteObjects(picasso);
objContext.commitChanges();