code: def setUp(self):
      super().setUp()
      self.pickle_prev = pkl5.pickle
      self.pickle = pkl5.Pickle()
      self.pickle.THRESHOLD = 0
      pkl5.pickle = self.pickle
  
imports: from mpi4py import MPI
  from mpi4py.util import pkl5
  import sys, os
label_desc: Use image node_id 1 for calling the BaseTestPKL5 obj's underlying member method code with example usage: obj.setUp() without return types