code: def testStruct1(self):
      shapes = [
          (),
          (1,),
          (3,),
          (3, 5),
      ]
      iter1 = itertools.product(shapes, typecodes)
      iter2 = itertools.product(shapes, typecodes)
      iterN = itertools.product(iter1, iter2)
      iterA = iter([False, True])
      for nt, align in itertools.product(iterN, iterA):
          s1, t1, s2, t2 = sum(nt, ())
          spec = f"{s1}{t1},{s2}{t2}"
          with self.subTest(spec=spec, align=align):
              self.check(spec, align)
  
imports: from mpi4py import MPI
  from mpi4py.util.dtlib import from_numpy_dtype
  from mpi4py.util.dtlib import to_numpy_dtype
  import sys, os
  import itertools
label_desc: Use image node_id 5 for calling the TestUtilDTLib obj's underlying member method code with example usage: obj.testStruct1() without return types