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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 _uniq_pixels_iterator(self):
 """ Generator giving the NUNIQ HEALPix pixels of the MOC. Returns ------- uniq : the NUNIQ HEALPix pixels iterator """

        intervals_uniq_l = IntervalSet.to_nuniq_interval_set(self._interval_set)._intervals
        for uniq_iv in intervals_uniq_l:
            for uniq in range(uniq_iv[0], uniq_iv[1]):
                yield uniq