code: def test_register_script(self):
      assert "test_script" in script.SCRIPT_REGISTRY
  
imports: import sys
  import unittest
  from unittest.mock import patch
  from parlai.core.params import ParlaiParser
  import parlai.core.script
  import parlai.utils.testing
label_desc: Use image node_id 2 for calling the TestScriptRegistry obj's underlying member method code with example usage: obj.test_register_script() without return types