code: def test_device_methods(
      self,
      num_ps,
      num_subnetworks,
      want_variable_devices,
      dedicate_parameter_servers=True,
  ):
      with context.graph_mode():
          x = tf.constant([[1.0, 0.0]])
          strategy = RoundRobinStrategy(
              dedicate_parameter_servers=dedicate_parameter_servers
          )
          strategy.config = ParameterServerConfig(num_ps)
          variable_devices = []
          for i in range(num_subnetworks):
              with strategy.subnetwork_devices(num_subnetworks, i):
                  subnetwork = tf.keras.Sequential()
                  subnetwork.add(tf.keras.layers.Dense(4))
                  subnetwork.add(tf.keras.layers.Dense(3))
                  subnetwork(x)
              variable_devices.append(
                  [w.op.device for w in subnetwork.weights]
              )
      self.assertEqual(want_variable_devices, variable_devices)
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import itertools
  from absl.testing import parameterized
  from adanet.distributed.placement import ReplicationStrategy
  from adanet.distributed.placement import RoundRobinStrategy
  import tensorflow.compat.v2
  from tensorflow.python.eager import context
  from tensorflow.python.framework import test_util
label_desc: Use image node_id 2 for calling the RoundRobinStrategyTest obj's underlying member method code with example usage: obj.test_device_methods(num_ps, num_subnetworks, want_variable_devices, dedicate_parameter_servers) without return types