code: def __call__(
      self, rest_endpoint, experiment_dir, nni_source_dir, **kwargs
  ):
      print(rest_endpoint)
      exp_id = osp.split(experiment_dir)[-1]
      rootpath = kwargs.get("rootpath")
  
      metrics = requests.get(METRICS_URL).json()
      for metric in metrics:
          trial_id = metric["trialJobId"]
          checkpath = osp.join(
              rootpath,
              "nni",
              exp_id,
              "trials",
              trial_id,
              "nnioutput",
              "checkingfile.txt",
          )
          print(
              "Checking shared storage log exists on trial ", trial_id
          )
          assert osp.exists(checkpath)
  
imports: import os.path
  from os import remove
  import subprocess
  import json
  import requests
  from nni.experiment import Experiment
  from nni.tools.nnictl.updater import load_imported_data
  from utils import METRICS_URL, GET_IMPORTED_DATA_URL
label_desc: Use image node_id 1 for calling the FileExistValidator obj's underlying member method code with example usage: obj.__call__(rest_endpoint, experiment_dir, nni_source_dir) without return types