code: def _walk_layers(keras_layer):
    
    yield ('', keras_layer)
    if keras_layer.get('config').get('layers'):
      name_scope = keras_layer.get('config').get('name')
      for layer in keras_layer.get('config').get('layers'):
        for (sub_name_scope, sublayer) in _walk_layers(layer):
          sub_name_scope = '%s/%s' % (
              name_scope, sub_name_scope) if sub_name_scope else name_scope
          yield (sub_name_scope, sublayer)
docs: Walks the nested keras layer configuration in preorder.
    Args:
      keras_layer: Keras configuration from model.to_json.
  
    Yields:
      A tuple of (name_scope, layer_config).
      name_scope: a string representing a scope name, similar to that of tf.name_scope.
      layer_config: a dict representing a Keras layer configuration.