code: def test_input_moved_to_cuda_device(self):
      if self.rank != 0:
          return
      dst_worker_name = dist_utils.worker_name(
          (self.rank + 1) % self.world_size
      )
  
      # These two CPU tensors (in args and kwargs) should be implicitly moved to an appropriate cuda device.
      t1 = torch.ones(1)
      args = (t1, 2)
      t2 = t1 * 2
      kwargs = dict(word=t2)
  
      # Only test Python nn.Module, because script module methods don't support taking kwargs.
      for remote_module in self._create_remote_module_iter(
          f"{dst_worker_name}/cuda:0",
          modes=[ModuleCreationMode.MODULE_CTOR],
      ):
          ret_fut = remote_module.forward_async(*args, **kwargs)
          ret = ret_fut.wait()
          self.assertEqual(ret, tuple(reversed(args + (t2,))))
          # TODO: Once the RPC backend can support directly sending GPU tensors, the expected device type should be "cuda:0".
          self.assertEqual(ret[0].device.type, "cpu")
          self.assertEqual(ret[2].device.type, "cpu")
  
          ret = remote_module.forward(*args, **kwargs)
          self.assertEqual(ret, tuple(reversed(args + (t2,))))
          # TODO: Once the RPC backend can support directly sending GPU tensors, the expected device type should be "cuda:0".
          self.assertEqual(ret[0].device.type, "cpu")
          self.assertEqual(ret[2].device.type, "cpu")
  
imports: import enum
  from typing import Tuple
  import torch
  import torch.distributed.rpc
  import torch.testing._internal.dist_utils
  from torch import Tensor, nn
  from torch._jit_internal import Future
  from torch.distributed.nn import RemoteModule
  from torch.distributed.nn.api.remote_module import _REMOTE_MODULE_PICKLED_ATTRIBUTES
  from torch.distributed.nn.api.remote_module import _RemoteModule
  from torch.testing._internal.common_distributed import skip_if_lt_x_gpu
  from torch.testing._internal.common_utils import TemporaryFileName
  from torch.testing._internal.distributed.rpc.rpc_agent_test_fixture import RpcAgentTestFixture
label_desc: Use image node_id 3 for calling the CudaRemoteModuleTest obj's underlying member method code with example usage: obj.test_input_moved_to_cuda_device() without return types