code: def test_single_tensor(self):
      input_data = {"img": torch.tensor([[0, 1], [1, 2]])}
      result = ConcatItemsd(keys="img", name="cat_img")(input_data)
      result["cat_img"] += 1
      assert_allclose(result["img"], torch.tensor([[0, 1], [1, 2]]))
      assert_allclose(result["cat_img"], torch.tensor([[1, 2], [2, 3]]))
  
file_path: MONAI/tests/test_concat_itemsd.py
imports: from __future__ import annotations
  import unittest
  import numpy
  import torch
  from monai.data import MetaTensor
  from monai.transforms import ConcatItemsd
  from tests.utils import assert_allclose
label_desc: Use image node_id 5 for calling the TestConcatItemsd obj's underlying member method code with example usage: obj.test_single_tensor() without return types