code: def test_get_strategy(self):
      self.assertIsNone(strategy_utils.get_strategy(None))
  
      self.assertIsInstance(
          strategy_utils.get_strategy("MirroredStrategy"),
          tf.distribute.MirroredStrategy,
      )
  
      self.assertIsInstance(
          strategy_utils.get_strategy("MultiWorkerMirroredStrategy"),
          tf.distribute.MultiWorkerMirroredStrategy,
      )
  
      with self.assertRaises(ValueError):
          strategy_utils.get_strategy("NotSupportedStrategy")
  
imports: import os
  import tensorflow
  from tensorflow_ranking.python.keras import strategy_utils
label_desc: Use image node_id 1 for calling the StrategyUtilsTest obj's underlying member method code with example usage: obj.test_get_strategy() without return types