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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 _sanity_check(self):
 """ Check if the time series have more than two data points. """

        if len(self.time_series_a) < 2 or len(self.time_series_b) < 2:
            raise exceptions.NotEnoughDataPoints('luminol.Correlator: Too few data points!')