code: def _generate_job_id():
      """Returns a unique job id prefixed with 'tf_train'."""
      # CAIP job id can contains only numbers, letters and underscores.
      unique_tag = str(uuid.uuid4()).replace("-", "_")
      return "tf_cloud_train_{}".format(unique_tag)
  
file_path: cloud/src/python/tensorflow_cloud/core/deploy.py
imports: import subprocess
  import uuid
  from .None import gcp
  from .None import machine_config
  from googleapiclient import discovery
  from googleapiclient import errors
  from ..utils import google_api_client
label_desc: Use image node_id 5 for calling a global function with example usage: _generate_job_id() and returns: str