code: def _bbox_to_area_polygon(self, bbox):
          
          projected_bbox = bbox.transform(self.crs)
          return projected_bbox.geometry
docs: Transforms bounding box into a polygon object in the area CRS.
  
          :param bbox: A bounding box
          :type bbox: BBox
          :return: A polygon
          :rtype: shapely.geometry.polygon.Polygon