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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 _estimate_count(self):
 """ Update the count number using the estimation of the unset ratio """

        if self.estimate_z == 0:
            self.estimate_z = (1.0 / self.nbr_bits)
        self.estimate_z = min(self.estimate_z, 0.999999)
        self.count = int(-(self.nbr_bits / self.nbr_slices) * np.log(1 - self.estimate_z))