code: def get(identifier):
      """Retrieves a Keras Optimizer instance.
  
      Args:
          identifier: Optimizer identifier, one of
              - String: name of an optimizer
              - Dictionary: configuration dictionary. - Keras Optimizer instance (it
                will be returned unchanged). - TensorFlow Optimizer instance (it
                will be wrapped as a Keras Optimizer).
  
      Returns:
          A Keras Optimizer instance.
  
      Raises:
          ValueError: If `identifier` cannot be interpreted.
      """
      if isinstance(identifier, (Optimizer, optimizer_v2.OptimizerV2)):
          return identifier
      # Wrap legacy TF optimizer instances
      elif isinstance(identifier, tf_optimizer_module.Optimizer):
          opt = TFOptimizer(identifier)
          backend.track_tf_optimizer(opt)
          return opt
      elif isinstance(identifier, dict):
          return deserialize(identifier)
      elif isinstance(identifier, str):
          config = {"class_name": str(identifier), "config": {}}
          return deserialize(config)
      else:
          raise ValueError(
              "Could not interpret optimizer identifier: {}".format(
                  identifier
              )
          )
  
file_path: tensorflow-upstream/tensorflow/python/keras/optimizers.py
imports: from tensorflow.python.keras import backend
  from tensorflow.python.keras.optimizer_v1 import Optimizer
  from tensorflow.python.keras.optimizer_v1 import TFOptimizer
  from tensorflow.python.keras.optimizer_v2 import adadelta
  from tensorflow.python.keras.optimizer_v2 import adagrad
  from tensorflow.python.keras.optimizer_v2 import adam
  from tensorflow.python.keras.optimizer_v2 import adamax
  from tensorflow.python.keras.optimizer_v2 import ftrl
  from tensorflow.python.keras.optimizer_v2 import gradient_descent
  from tensorflow.python.keras.optimizer_v2 import nadam
  from tensorflow.python.keras.optimizer_v2 import optimizer_v2
  from tensorflow.python.keras.optimizer_v2 import rmsprop
  from tensorflow.python.keras.utils.generic_utils import deserialize_keras_object
  from tensorflow.python.keras.utils.generic_utils import serialize_keras_object
  from tensorflow.python.training import optimizer
label_desc: Use image node_id 3 for calling a global function with example usage: get(identifier) and returns: identifier, opt, deserialize, deserialize