code: def test_scan(self):
      rank = self.comm.rank
      size = self.comm.size
      msg = rank
      res = self.comm.scan(sendobj=msg)
      self.assertEqual(res, sum(list(range(size))[: rank + 1]))
  
imports: from mpi4py import MPI
  import unittest
  import sys, os
  from reductions import Intracomm
label_desc: Use image node_id 11 for calling the BaseTest obj's underlying member method code with example usage: obj.test_scan() without return types