code: def testAddressOf(self):
      for obj in self.objects:
          addr = MPI._addressof(obj)
          self.assertNotEqual(addr, 0)
      with self.assertRaises(TypeError):
          MPI._addressof(None)
  
imports: from mpi4py import MPI
  import mpiunittest
  import ctypes
  import operator
  import weakref
  import sys
label_desc: Use image node_id 12 for calling the TestObjModel obj's underlying member method code with example usage: obj.testAddressOf() without return types