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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 _maybe_resample(self):
 """ Checks the resample threshold and conditionally resamples. """

        ess = self.n_ess
        if ess <= 10:
            warnings.warn(
                "Extremely small n_ess encountered ({}). "
                "Resampling is likely to fail. Consider adding particles, or "
                "resampling more often.".format(ess),
                ApproximationWarning
            )
        if ess < self.n_particles * self.resample_thresh:
            self.resample()
            pass