code: def test_single_value(self, device, dtype):
      # prepare input data
      mean = torch.tensor(2, device=device, dtype=dtype)
      std = torch.tensor(3, device=device, dtype=dtype)
      data = torch.ones(2, 3, 256, 313, device=device, dtype=dtype)
  
      # expected output
      expected = (data * std) + mean
  
      self.assert_close(
          kornia.enhance.denormalize(data, mean, std), expected
      )
  
imports: import pytest
  import torch
  from torch.autograd import gradcheck
  import kornia
  import kornia.testing
  from kornia.testing import BaseTester
label_desc: Use image node_id 8 for calling the TestDenormalize obj's underlying member method code with example usage: obj.test_single_value(device, dtype) without return types