message: Use first worker as default device in tf_function_test.
diff: @@ -50,7 +50,11 @@ class TFFunctionTest(test.TestCase, parameterized.TestCase):
  self, distribution, run_functions_eagerly):
  def_function.run_functions_eagerly(run_functions_eagerly)
  - expected_device = (device_util.canonicalize("cpu:0")
  + try:
  + worker = distribution.extended.worker_devices[0]
  + except RuntimeError:
  + worker = None
  + expected_device = (device_util.canonicalize("cpu:0", worker)
  if run_functions_eagerly else "")
  with distribution.scope():
  with ops.device_v2("cpu:0"):
  @@ -72,7 +76,11 @@ class TFFunctionTest(test.TestCase, parameterized.TestCase):
  self, distribution, run_functions_eagerly):
  def_function.run_functions_eagerly(run_functions_eagerly)
  - expected_device = (device_util.canonicalize("cpu:0")
  + try:
  + worker = distribution.extended.worker_devices[0]
  + except RuntimeError:
  + worker = None
  + expected_device = (device_util.canonicalize("cpu:0", worker)
  if run_functions_eagerly else "")
  with distribution.scope():
  @def_function.function
  