code: def testUnknownDeviceInFunction(self):
      @def_function.function
      def f():
          with ops.device("GPU:42"):
              # With placer, the unknown GPU:42 will be replaced with GPU:0.
              a = constant_op.constant(1) + constant_op.constant(2)
          return a + constant_op.constant(2)
  
      gpus = config.list_physical_devices("GPU")
      if not gpus:
          self.assertIn("CPU:0", f().device)
      else:
          self.assertIn("GPU:0", f().device)
  
imports: from absl.testing import parameterized
  from tensorflow.python.eager import context
  from tensorflow.python.eager import def_function
  from tensorflow.python.eager import remote
  from tensorflow.python.eager import test
  from tensorflow.python.framework import config
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import errors
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import math_ops
  from tensorflow.python.ops import random_ops
label_desc: Use image node_id 12 for calling the SoftDevicePlacementTest obj's underlying member method code with example usage: obj.testUnknownDeviceInFunction() and returns: unknown