code: def download(cls, architecture, path="./"):
      if cls.sanity_check(architecture):
          architecture_file = download_file(
              cls.architecture_map[architecture]["url"],
              directory=path,
              auto_unzip=True,
          )
          if not architecture_file:
              return None
  
          tf.reset_default_graph()
  
          if "ckpt" in cls.architecture_map[architecture]["filename"]:
              cls.handle_checkpoint(architecture, path)
  
          elif cls.architecture_map[architecture]["filename"].endswith(
              "pb"
          ):
              cls.handle_frozen_graph(architecture, path)
  
          else:
              raise ValueError(
                  "Unknown file name [{}].".format(
                      cls.architecture_map[architecture]["filename"]
                  )
              )
  
          return architecture_file
  
      else:
          return None
  
imports: from __future__ import absolute_import
  import os
  import tensorflow
  from tensorflow.contrib.slim.nets import vgg
  from tensorflow.contrib.slim.nets import inception
  from tensorflow.contrib.slim.nets import resnet_v1
  from tensorflow.contrib.slim.nets import resnet_v2
  from mmdnn.conversion.examples.tensorflow.models import inception_resnet_v2
  from mmdnn.conversion.examples.tensorflow.models import mobilenet_v1
  from mmdnn.conversion.examples.tensorflow.models import nasnet
  from mmdnn.conversion.examples.tensorflow.models.mobilenet import mobilenet_v2
  from mmdnn.conversion.examples.tensorflow.models import inception_resnet_v1
  from mmdnn.conversion.examples.tensorflow.models import test_rnn
  from mmdnn.conversion.examples.imagenet_test import TestKit
  from mmdnn.conversion.examples.extractor import base_extractor
  from mmdnn.conversion.common.utils import download_file
label_desc: Use image node_id 4 for calling the tensorflow_extractor obj's underlying member method code with example usage: obj.download(cls, architecture, path) and returns: architecture_file, None, None