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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 check_w3_time (self):
 """Make sure the W3C validators are at most called once a second."""

        if time.time() - self.last_w3_call < W3Timer.SleepSeconds:
            time.sleep(W3Timer.SleepSeconds)
        self.last_w3_call = time.time()