code: def bottoms(panels):
      
      bottom_lines = [(p['col'], p['row'] + p['size_y'], p['col'] + p['size_x'], p['row'] + p['size_y']) for p in panels]
      return sorted(bottom_lines, key=lambda l: l[1], reverse=True)
docs: Finds bottom lines of all panels
      :param panels:
      :return: sorted by row list of tuples representing lines (col, row , col + len, row)