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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 duration_expired(start_time, duration_seconds):
 """ Return True if ``duration_seconds`` have expired since ``start_time`` """


    if duration_seconds is not None:
        delta_seconds = datetime_delta_to_seconds(dt.datetime.now() - start_time)

        if delta_seconds >= duration_seconds:
            return True

    return False