code: def testF90Complex(self):
      try:
          mt = MPI.Datatype.Create_f90_complex(7, MPI.UNDEFINED)
          if mt == MPI.DATATYPE_NULL or mt.Get_size() == 0:
              raise NotImplementedError
      except NotImplementedError:
          self.skipTest("mpi-type-create-f90-complex")
      for p in (6, 7, 14, 15):
          with self.subTest(p=p):
              mt = MPI.Datatype.Create_f90_complex(p, MPI.UNDEFINED)
              dt = tonumpy(mt)
              if np_dtype is not None:
                  self.assertEqual(dt.kind, "c")
                  self.assertEqual(dt.itemsize, mt.extent)
  
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 19 for calling the TestUtilDTLib obj's underlying member method code with example usage: obj.testF90Complex() without return types