docstr: 测试单个张量的设备和梯度转换是否正确
docstr_tok: ["\u6d4b\u8bd5\u5355\u4e2a\u5f20\u91cf\u7684\u8bbe\u5907\u548c\u68af\u5ea6\u8f6c\u6362\u662f\u5426\u6b63\u786e"]
code: def test_tensor_transfer(self):
      """
      测试单个张量的设备和梯度转换是否正确
      """
  
      paddle_tensor = paddle.rand((3, 4, 5)).cpu()
      res = paddle2torch(paddle_tensor)
      self.check_torch_tensor(
          res, "cpu", not paddle_tensor.stop_gradient
      )
  
      res = paddle2torch(
          paddle_tensor, device="cuda:2", no_gradient=None
      )
      self.check_torch_tensor(
          res, "cuda:2", not paddle_tensor.stop_gradient
      )
  
      res = paddle2torch(
          paddle_tensor, device="cuda:1", no_gradient=True
      )
      self.check_torch_tensor(res, "cuda:1", False)
  
      res = paddle2torch(
          paddle_tensor, device="cuda:1", no_gradient=False
      )
      self.check_torch_tensor(res, "cuda:1", True)
  
imports: import pytest
  from fastNLP.envs.imports import _NEED_IMPORT_JITTOR, _NEED_IMPORT_PADDLE, _NEED_IMPORT_TORCH
  from fastNLP.modules.mix_modules.utils import paddle2torch, torch2paddle, jittor2torch, torch2jittor
label_desc: Use image node_id 3 for calling the TestPaddle2Torch obj's underlying member method code with example usage: obj.test_tensor_transfer() without return types