code: def test_model_register_unregister():
      reg_resp = test_utils.register_model(
          "dcgan_fashiongen", "dcgan_fashiongen.mar"
      )
      assert reg_resp.status_code == 200, "Model Registration Failed"
  
      unreg_resp = test_utils.unregister_model("dcgan_fashiongen")
      assert (
          unreg_resp.status_code == 200
      ), "Model Unregistration Failed"
  
file_path: serve/test/pytest/test_example_dcgan.py
imports: import os
  import subprocess
  import requests
  import test_utils
  from shutil import copy
  from PIL import Image
  from io import BytesIO
label_desc: Use image node_id 6 for calling a global function with example usage: test_model_register_unregister() without return types