code: def num_clients() -> int:
      """Returns the number of clients in this DTensor cluster."""
      if is_local_mode():
          return 1
      return len(jobs())
  
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 5 for calling a global function with example usage: num_clients() and returns: len, int