code: def test_case(self):
      tensor = paddle.rand((4, 5))
  
      res = paddle_to(tensor, "gpu")
      assert res.place.is_gpu_place()
      assert res.place.gpu_device_id() == 0
      res = paddle_to(tensor, "cpu")
      assert res.place.is_cpu_place()
  
file_path: fastNLP/tests/core/utils/test_paddle_utils.py
imports: import os
  import pytest
  from fastNLP.core.utils.paddle_utils import _convert_data_device, paddle_to, paddle_move_data_to_device
  from fastNLP.envs.imports import _NEED_IMPORT_PADDLE
label_desc: Use image node_id 1 for calling the TestPaddleToDevice obj's underlying member method code with example usage: obj.test_case() without return types