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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 _delay_for_ratelimits(cls, start):
 """If request was shorter than max request time, delay"""

        stop = datetime.now()
        duration_microseconds = (stop - start).microseconds
        if duration_microseconds < cls.REQUEST_TIME_MICROSECONDS:
            time.sleep((cls.REQUEST_TIME_MICROSECONDS - duration_microseconds)
                       / MICROSECONDS_PER_SECOND)