code: def test(self):
      self.assertNotIn("test_regrtest_a", sys.modules)
      self.assertIn("test_regrtest_b", sys.modules)
      self.assertNotIn("test_regrtest_b.util", sys.modules)
      self.assertNotIn("test_regrtest_c", sys.modules)
  
imports: import sys
  import unittest
label_desc: Use image node_id 1 for calling the Test obj's underlying member method code with example usage: obj.test() without return types