code: def test(self):
      test_regrtest_b.util  # does not fail
      self.assertIn("test_regrtest_a", sys.modules)
      self.assertIs(sys.modules["test_regrtest_b"], test_regrtest_b)
      self.assertIs(
          sys.modules["test_regrtest_b.util"], test_regrtest_b.util
      )
      self.assertNotIn("test_regrtest_c", sys.modules)
  
imports: import sys
  import unittest
  import test_regrtest_b.util
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