code: def test_from_local_then_to_local(self):
      # this test ensure end to end from torch.Tensor -> dist tensor -> torch.Tensor works
      device_mesh = DeviceMesh(
          self.device_type, list(range(self.world_size))
      )
      placements = [Shard(0)]
  
      # step 1. construct from construct local tensor
      local_tensor_with_grad = torch.randn(
          3, 3, device=self.device_type, requires_grad=True
      )
      # do some operations on local tensor
      local_tensor_temp = local_tensor_with_grad + 8
      # step 2. create the dist tensor with non leaf local tensor, dist tensor
      # created should also be non leaf node
      dist_tensor = DTensor.from_local(
          local_tensor_temp, device_mesh, placements
      )
      self.assertFalse(dist_tensor.is_leaf)
      # do some random operations on dist tensor
      output = dist_tensor * 6
      self.assertIsInstance(output, DTensor)
  
      # step 3. do some operation on local tensor of the dist tensor
      new_tensor_with_grad = torch.randn(
          3, 3, device=self.device_type, requires_grad=True
      )
      res = output.to_local() + new_tensor_with_grad
      # call backward directly on torch.Tensor, and see if it works by
      # propagating all the way back to the original torch.Tensor
      res.sum().backward()
      self.assertIsNotNone(local_tensor_with_grad.grad)
  
      expected_grad = torch.ones(3, 3) * 6
      self.assertEqual(local_tensor_with_grad.grad, expected_grad)
  
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 15 for calling the DTensorTest obj's underlying member method code with example usage: obj.test_from_local_then_to_local() without return types