code: def __define_graph(self):
      (
          self.optimizer,
          self.loss,
          self.output,
      ) = define_style_transfer_network(
          self.tf_input,
          self.tf_index,
          self.tf_style,
          self._tf_variables,
          self._define_training_graph,
      )
  
imports: from __future__ import print_function
  from __future__ import division
  from __future__ import absolute_import
  from turicreate.toolkits._tf_model import TensorFlowModel
  import numpy
  import turicreate.toolkits._tf_utils
  from turicreate._deps.minimal_package import _minimal_package_import_check
label_desc: Use image node_id 4 for calling the StyleTransferTensorFlowModel obj's underlying member method code with example usage: obj.__define_graph() without return types