class_docstr: Tests for mesh_util that require accelerator initialization.
class_docstr_tok: ["Tests","for","mesh_util","that","require","accelerator","initialization","."]
code: def test_mesh_barrier(self):
      device_type = config.preferred_device_type()
  
      num_devices = len(
          test_util.list_local_logical_devices(device_type)
      )
      mesh = mesh_util.create_mesh(
          [("dim", num_devices)], device_type=device_type
      )
  
      # FIXME(b/235416015): To really test this we'll need a new eager async
      # API.  The following shall run, but the barrier semantics is not tested.
      mesh_util.barrier(mesh, "Name")
      mesh_util.barrier(mesh)
  
imports: import os
  from unittest import mock
  from absl.testing import parameterized
  from tensorflow.dtensor.python import accelerator_util
  from tensorflow.dtensor.python import config
  from tensorflow.dtensor.python import mesh_util
  from tensorflow.dtensor.python.tests import test_util
  from tensorflow.python.eager import context
  from tensorflow.python.framework import config
  from tensorflow.python.framework import device
  from tensorflow.python.platform import test
label_desc: Use image node_id 12 for calling the InitializedMeshUtilTest obj's underlying member method code with example usage: obj.test_mesh_barrier() without return types