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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _wait_for_save(nb_name, timeout=5):
 """Waits for nb_name to update, waiting up to TIMEOUT seconds. Returns True if a save was detected, and False otherwise. """

    modification_time = os.path.getmtime(nb_name)
    start_time = time.time()
    while time.time() < start_time + timeout:
        if (
            os.path.getmtime(nb_name) > modification_time
            and os.path.getsize(nb_name) > 0
        ):
            return True
        time.sleep(0.2)
    return False