code: def find_side(ls, side):
      
      minx, miny, maxx, maxy = ls.bounds
      points = {'left': [(minx, miny), (minx, maxy)],
                'right': [(maxx, miny), (maxx, maxy)],
                'bottom': [(minx, miny), (maxx, miny)],
                'top': [(minx, maxy), (maxx, maxy)],}
      return sgeom.LineString(points[side])
docs: Given a shapely LineString which is assumed to be rectangular, return the
      line corresponding to a given side of the rectangle.