Transforms BBoxCollection from current CRS to target CRS

        :param crs: target CRS
        :type crs: constants.CRS
        :return: BBoxCollection in target CRS
        :rtype: BBoxCollection

def transform(self, crs):
        """ Transforms BBoxCollection from current CRS to target CRS

        :param crs: target CRS
        :type crs: constants.CRS
        :return: BBoxCollection in target CRS
        :rtype: BBoxCollection
        """
        return BBoxCollection([bbox.transform(crs) for bbox in self.bbox_list])