code: def jobs() -> List[str]:
      """Returns a list of job names of all clients in this DTensor cluster."""
      d_jobs = os.environ.get(_DT_JOBS)
      if d_jobs is None:
          return []
      d_jobs_list = d_jobs.split(",")
  
      # Validate ordering for BNS style job names.
      # For definition of BNS, refer to https://research.google/pubs/pub43438/.
      if any([name.startswith("/bns/") for name in d_jobs_list]):
          if d_jobs_list != sorted(d_jobs_list, key=_bns_task_id):
              raise ValueError(
                  f"Unexpected DTENSOR_JOBS content {d_jobs}. Sort entries "
                  "in DTENSOR_JOBS because cluster construction relies on "
                  "the order."
              )
  
      return d_jobs_list
  
imports: import os
  from typing import List, Optional, Union
  from tensorflow.python.eager import context
  from tensorflow.python.framework import config
  from tensorflow.python.framework import device
  from tensorflow.python.util.tf_export import tf_export
label_desc: Use image node_id 9 for calling a global function with example usage: jobs() and returns: d_jobs_list, list