code: def testPickle(self):
      from pickle import dumps, loads
  
      with self.assertRaises(ValueError):
          loads(dumps(self.FILE))
  
imports: from mpi4py import MPI
  import mpiunittest
  import os, tempfile, pathlib
label_desc: Use image node_id 17 for calling the BaseTestFile obj's underlying member method code with example usage: obj.testPickle() without return types