code: def test_dtensor_save_load(self):
      import io
  
      device_mesh = self.build_device_mesh()
      placements = [Shard(0)]
      local_tensor = torch.randn(3, 3)
      sharded_tensor = DTensor.from_local(
          local_tensor, device_mesh, placements
      )
      buffer = io.BytesIO()
      torch.save(sharded_tensor, buffer)
      buffer.seek(0)
      reloaded_st = torch.load(buffer)
      self.assertEqual(sharded_tensor, reloaded_st)
  
imports: import torch
  import torch.nn.functional
  from numpy.testing import assert_array_equal
  from torch.distributed._functional_collectives import AsyncCollectiveTensor
  from torch.distributed._tensor import DeviceMesh, distribute_tensor, DTensor, init_device_mesh
  from torch.distributed._tensor.placement_types import _Partial, Replicate, Shard
  from torch.distributed.tensor.parallel import ColwiseParallel, parallelize_module, RowwiseParallel
  from torch.testing._internal.common_utils import run_tests
  from torch.testing._internal.distributed._tensor.common_dtensor import DTensorTestBase, with_comms
label_desc: Use image node_id 19 for calling the DTensorTest obj's underlying member method code with example usage: obj.test_dtensor_save_load() without return types