code: def test_gradcheck(self, device, dtype):
      B, C, H, W = 2, 3, 4, 4
      img = torch.rand(
          B,
          C,
          H,
          W,
          device=device,
          dtype=torch.float64,
          requires_grad=True,
      )
      img = kornia.color.rgb_to_luv(img)
      assert gradcheck(
          kornia.color.luv_to_rgb,
          (img,),
          raise_exception=True,
          fast_mode=True,
      )
  
imports: import pytest
  import torch
  from torch.autograd import gradcheck
  import kornia
  from kornia.testing import BaseTester
label_desc: Use image node_id 6 for calling the TestLuvToRgb obj's underlying member method code with example usage: obj.test_gradcheck(device, dtype) without return types