code: def test_display_model(self):
      from parlai.scripts.display_model import DisplayModel
  
      with testing_utils.capture_output() as output:
          DisplayModel.main(
              model="fixed_response",
              fixed_response="1 2 3 4",
              task="integration_tests",
              verbose=True,
          )
  
      output = output.getvalue()
      assert "metrics" in output
      assert "accuracy" in output
      assert "1 2 3 4" in output
  
imports: import os
  import unittest
  from parlai.core.message import Message
  from parlai.core.mutators import MessageMutator, register_mutator
  import parlai.utils.testing
label_desc: Use image node_id 1 for calling the TestDisplayModel obj's underlying member method code with example usage: obj.test_display_model() without return types