code: def testIsInitialized(self):
      flag = MPI.Is_initialized()
      self.assertIs(type(flag), bool)
      self.assertTrue(flag)
  
imports: from mpi4py import MPI
  import mpiunittest
  import os
label_desc: Use image node_id 1 for calling the TestEnviron obj's underlying member method code with example usage: obj.testIsInitialized() without return types