code: def testSubarray1(self):
      shapes = [
          (1,),
          (1, 1),
          (1, 1, 1),
          (3,),
          (3, 4),
          (2, 3, 4),
      ]
      for dt, shape in itertools.product(typecodes, shapes):
          spec = f"{shape}{dt}"
          with self.subTest(spec=spec):
              self.check(spec)
  
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 3 for calling the TestUtilDTLib obj's underlying member method code with example usage: obj.testSubarray1() without return types