code: def test_reviving_functional_from_config_custom_layer(self):
      class CustomDense(layers.Layer):
          def __init__(self, units, **kwargs):
              super().__init__(**kwargs)
              self.dense = layers.Dense(units)
  
          def call(self, x):
              return self.dense(x)
  
      inputs = layers.Input((4,))
      outputs = CustomDense(10)(inputs)
      model = Model(inputs, outputs)
      config = model.get_config()
  
      new_model = Model.from_config(
          config, custom_objects={"CustomDense": CustomDense}
      )
      self.assertIsInstance(new_model, Functional)
  
imports: import numpy
  import pytest
  from absl.testing import parameterized
  from keras import layers
  from keras import testing
  from keras.layers.core.input_layer import Input
  from keras.models.functional import Functional
  from keras.models.model import Model
  from keras.models.model import model_from_json
label_desc: Use image node_id 4 for calling the ModelTest obj's underlying member method code with example usage: obj.test_reviving_functional_from_config_custom_layer() and returns: self