code: def test_msssim_equal_none(self, device, dtype):
      # input data
      img1 = torch.rand(1, 3, 10, 16, device=device, dtype=dtype)
      img2 = torch.rand(1, 3, 10, 16, device=device, dtype=dtype)
  
      msssim = kornia.losses.MS_SSIMLoss().to(device, dtype)
      msssim1 = msssim(img1, img1)
      msssim2 = msssim(img2, img2)
  
      assert_close(msssim1.item(), 0.0)
      assert_close(msssim2.item(), 0.0)
  
imports: import pytest
  import torch
  from torch.autograd import gradcheck
  import kornia
  import kornia.testing
  from kornia.testing import BaseTester, assert_close
label_desc: Use image node_id 1 for calling the TestMS_SSIMLoss obj's underlying member method code with example usage: obj.test_msssim_equal_none(device, dtype) without return types