def _remove_duplicates(self):
        """
        Remove every maximal rectangle contained by another one.
        """
        contained = set()
        for m1, m2 in itertools.combinations(self._max_rects, 2):
            if m1.contains(m2):
                contained.add(m2)
            elif m2.contains(m1):
                contained.add(m1)
        
        # Remove from max_rects
        self._max_rects = [m for m in self._max_rects if m not in contained]
Remove every maximal rectangle contained by another one.