code: def _down_convert_polyline_points(d):
      if not isinstance(d, dict):
          return False
  
      cls = d.get("_cls", None)
      if cls == "Polyline":
          if "points" not in d:
              return False
  
          if len(d["points"]) != 1:
              d["points"] = [[]]
          else:
              d["points"] = d["points"][0]
  
          return True
  
      if cls == "Polylines":
          for polyline in d.get("polylines", []):
              _down_convert_polyline_points(polyline)
  
          return True
  
      return False
  
imports: import pymongo
label_desc: Use image node_id 3 for calling a global function with example usage: _down_convert_polyline_points(d) and returns: False, False, True, True, False