docstr: Test if the environment uses the correct port
  when the environment file is provided
docstr_tok: ["Test","if","the","environment","uses","the","correct","port","when","the","environment","file","is","provided"]
code: def test_port_app(self, mock_unity3d):
      """Test if the environment uses the correct port
      when the environment file is provided"""
  
      _ = Unity3DEnv(file_name="app", port=None)
      args, kwargs = mock_unity3d.call_args
      mock_unity3d.assert_called_once()
      self.assertEqual(5005, kwargs.get("base_port"))
  
file_path: ray/rllib/env/wrappers/tests/test_unity3d_env.py
imports: import unittest
  from unittest.mock import patch
  from ray.rllib.env.wrappers.unity3d_env import Unity3DEnv
label_desc: Use image node_id 2 for calling the TestUnity3DEnv obj's underlying member method code with example usage: obj.test_port_app(mock_unity3d) without return types