code: def create_dispatcher(test_name, worker_addresses, port, pipe=None):
      dispatcher = server_lib.DispatchServer(
          config=server_lib.DispatcherConfig(
              port=port,
              protocol="grpc",
              worker_addresses=worker_addresses,
          )
      )
      dispatcher.start()
      if pipe is None:
          # Dispatcher is not within subprocess, so do not block.
          return dispatcher, dispatcher._address
      else:
          redirect_output(f"test-{test_name}-dispatcher.log")
          pipe.send(dispatcher._address)
          signal = (
              pipe.recv()
          )  # blocks until a 'stop' signal is received
          if signal == "stop":
              dispatcher._stop()
              pipe.send("stopped")
          else:
              raise ValueError("Got unknown signal %s" % signal)
  
imports: import os
  from typing import Any, List, Mapping, Optional, Tuple
  from absl import logging
  from absl.testing import parameterized
  import numpy
  from tensorflow.core.example import example_pb2
  from tensorflow.core.example import feature_pb2
  from tensorflow.dtensor.python import accelerator_util
  from tensorflow.dtensor.python import api
  from tensorflow.dtensor.python import config
  from tensorflow.dtensor.python import input_util
  from tensorflow.dtensor.python import layout
  from tensorflow.dtensor.python import mesh_util
  from tensorflow.dtensor.python.tests import multi_client_test_util
  from tensorflow.dtensor.python.tests import test_backend_util
  from tensorflow.dtensor.python.tests import test_util
  from tensorflow.python.data.experimental.service import server_lib
  from tensorflow.python.data.ops import dataset_ops
  from tensorflow.python.data.ops import readers
  from tensorflow.python.eager import context
  from tensorflow.python.framework import config
  from tensorflow.python.framework import device_spec
  from tensorflow.python.framework import dtypes
  from tensorflow.python.lib.io import tf_record
  from tensorflow.python.ops import array_ops_stack
  from tensorflow.python.ops import check_ops
  from tensorflow.python.ops import gen_parsing_ops
  from tensorflow.python.ops import io_ops
  from tensorflow.python.ops import parsing_config
  from tensorflow.python.ops import parsing_ops
  from tensorflow.python.ops import stateless_random_ops
  from tensorflow.python.platform import test
label_desc: Use image node_id 2 for calling a global function with example usage: create_dispatcher(test_name, worker_addresses, port, pipe) and returns: dispatcher,  dispatcher