code: def _insert_new_layers(self, new_layers, start_node_id, end_node_id):
          
          new_node_id = self._add_node(deepcopy(self.node_list[end_node_id]))
          temp_output_id = new_node_id
          for layer in new_layers[:-1]:
              temp_output_id = self.add_layer(layer, temp_output_id)
  
          self._add_edge(new_layers[-1], temp_output_id, end_node_id)
          new_layers[-1].input = self.node_list[temp_output_id]
          new_layers[-1].output = self.node_list[end_node_id]
          self._redirect_edge(start_node_id, end_node_id, new_node_id)
docs: Insert the new_layers after the node with start_node_id.