def METHOD_NAME(self):
    journal = []
    def progress(status, remaining, total):
        if not journal:
            self.cx.execute('INSERT INTO foo (key) VALUES (?)', (remaining+1000,))
            self.cx.commit()
        journal.append(remaining)
    with sqlite.connect(':memory:') as bck:
        self.cx.backup(bck, pages=1, progress=progress)
        self.verify_backup(bck)
        result = bck.execute("SELECT key FROM foo"
                             " WHERE key >= 1000"
                             " ORDER BY key").fetchall()
        self.assertEqual(result[0][0], 1001)
    self.assertEqual(len(journal), 3)
    self.assertEqual(journal[0], 1)
    self.assertEqual(journal[1], 1)
    self.assertEqual(journal[2], 0)