code: def _serialize_nested_config(config):
      """Serialized a nested structure of Keras objects."""
  
      def _serialize_fn(obj):
          if callable(obj):
              return generic_utils.serialize_keras_object(obj)
          return obj
  
      return nest.map_structure(_serialize_fn, config)
  
imports: import collections
  import copy
  import os
  from tensorflow.python.eager import def_function
  from tensorflow.python.keras import backend
  from tensorflow.python.keras import losses
  from tensorflow.python.keras import optimizer_v1
  from tensorflow.python.keras import optimizers
  from tensorflow.python.keras.engine import base_layer_utils
  from tensorflow.python.keras.utils import generic_utils
  from tensorflow.python.keras.utils import version_utils
  from tensorflow.python.keras.utils.io_utils import ask_to_proceed_with_overwrite
  from tensorflow.python.platform import tf_logging
  from tensorflow.python.util import nest
label_desc: Use image node_id 9 for calling a global function with example usage: _serialize_nested_config(config) and returns: nest, obj, generic_utils