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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 resample(self, data, stats=None, mask=None, niter=None):
 """ Introduce a mask that allows for missing data """

        stats = self._get_statistics(data, mask=mask) if stats is None else stats
        stats = self._stats_ensure_array(stats)

        niter = niter if niter else self.niter
        for itr in range(niter):
            self._resample_A(stats)
            self._resample_sigma(stats)