code: def test_function(self):
      @require_pkg(
          pkg_name="torch", version="1.4", version_checker=min_version
      )
      def test_func(x):
          return x
  
      test_func(x=None)
  
file_path: MONAI/tests/test_require_pkg.py
imports: from __future__ import annotations
  import unittest
  from monai.utils import OptionalImportError, min_version, require_pkg
label_desc: Use image node_id 2 for calling the TestRequirePkg obj's underlying member method code with example usage: obj.test_function() and returns: x