code: def test_unit(self, device, dtype):
      img_a = torch.tensor(
          [
              [
                  [
                      [
                          [0.7, 1.0, 0.5],
                          [1.0, 0.3, 1.0],
                          [0.2, 1.0, 0.1],
                      ],
                      [
                          [0.2, 1.0, 0.1],
                          [1.0, 0.3, 1.0],
                          [0.7, 1.0, 0.5],
                      ],
                      [
                          [1.0, 0.3, 1.0],
                          [0.7, 1.0, 0.5],
                          [0.2, 1.0, 0.1],
                      ],
                  ]
              ]
          ],
          device=device,
          dtype=dtype,
      )
  
      img_b = (
          torch.ones(1, 1, 3, 3, 3, device=device, dtype=dtype) * 0.5
      )
  
      actual = kornia.metrics.ssim3d(img_a, img_b, 3, padding="same")
  
      expected = torch.tensor(
          [
              [
                  [
                      [
                          [0.0093, 0.0080, 0.0075],
                          [0.0075, 0.0068, 0.0063],
                          [0.0067, 0.0060, 0.0056],
                      ],
                      [
                          [0.0077, 0.0070, 0.0065],
                          [0.0077, 0.0069, 0.0064],
                          [0.0075, 0.0066, 0.0062],
                      ],
                      [
                          [0.0075, 0.0069, 0.0064],
                          [0.0078, 0.0070, 0.0065],
                          [0.0077, 0.0067, 0.0064],
                      ],
                  ]
              ]
          ],
          device=device,
          dtype=dtype,
      )
  
      self.assert_close(actual, expected, atol=1e-4, rtol=1e-4)
  
imports: import pytest
  import torch
  import kornia
  from kornia.testing import BaseTester, assert_close, tensor_to_gradcheck_var
label_desc: Use image node_id 4 for calling the TestSSIM3d obj's underlying member method code with example usage: obj.test_unit(device, dtype) without return types