code: def _get_abstract_layer_name(self):
      
      abstract_layers = []
      for layer in self.model.layers:
        if 'layers' in layer.get_config():
          abstract_layers.append(layer.name)
  
      return abstract_layers
docs: Looks for the name of abstracted layer.
      Usually these layers appears when model is stacked.
      :return: List of abstracted layers