updater = new Updater(database, Updater.Method.Subtract);
Item item = new Item(updater.getDatabase(), "customer1");
assertTrue(item.getTags().contains("customer"));
item = new Item(updater.getDatabase(), "customer1");
item.removeTag("customer");
updater.export(item);
updater.finish();
item = new Item(updater.getDatabase(), "customer1");
assertFalse(item.getTags().contains("customer"));