code: def query_string(self) -> str:
      query_string = ""
      if len(self.query) > 0:
          query_string = f"?{self.query}"
      return query_string
  
imports: from __future__ import annotations
  import copy
  import os
  import re
  from typing import Optional
  from typing import Union
  from urllib.parse import urlparse
  import requests
  from typing_extensions import Self
  from ..serde.serializable import serializable
  from ..util.util import verify_tls
label_desc: Use image node_id 5 for calling the GridURL obj's underlying member method code with example usage: obj.query_string() and returns: query_string