code: def test_smoke(self, device, dtype):
      C, H, W = 3, 4, 6
      img = torch.rand(C, H, W, device=device, dtype=dtype)
      assert isinstance(
          kornia.color.rgb_to_raw(img, kornia.color.raw.CFA.BG),
          torch.Tensor,
      )
  
imports: import warnings
  import pytest
  import torch
  from packaging import version
  from torch.autograd import gradcheck
  import kornia
  from kornia.testing import BaseTester, assert_close
label_desc: Use image node_id 1 for calling the TestRgbToRaw obj's underlying member method code with example usage: obj.test_smoke(device, dtype) without return types