code: def test_cardinality(self, device, dtype, batch_size, height, width):
      img = torch.ones(
          batch_size, 1, height, width, device=device, dtype=dtype
      )
      assert kornia.color.grayscale_to_rgb(img).shape == (
          batch_size,
          3,
          height,
          width,
      )
  
imports: import pytest
  import torch
  from torch.autograd import gradcheck
  import kornia
  from kornia.testing import BaseTester, assert_close
  from kornia.utils._compat import torch_version
label_desc: Use image node_id 2 for calling the TestGrayscaleToRgb obj's underlying member method code with example usage: obj.test_cardinality(device, dtype, batch_size, height, width) without return types