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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_call(self):
 """ Makes sure that web service calls are at least 0.2 seconds apart. """

        now = time.time()

        time_since_last = now - self.last_call_time

        if time_since_last < DELAY_TIME:
            time.sleep(DELAY_TIME - time_since_last)

        self.last_call_time = now