code: def gcs_index():
      """The default handler for GCS requests."""
      return "OK"
  
imports: import argparse
  import error_response
  import flask
  import gcs_bucket
  import gcs_object
  import json
  import os
  import re
  import testbench_utils
  import time
  import sys
  from werkzeug import serving
  from werkzeug.middleware.dispatcher import DispatcherMiddleware
label_desc: Use image node_id 8 for calling a global function with example usage: gcs_index() and returns: str