code: def test_opencv(self, device, dtype):
      data = torch.tensor(
          [
              [
                  [
                      0.3944633,
                      0.8597369,
                      0.1670904,
                      0.2825457,
                      0.0953912,
                  ],
                  [
                      0.1251704,
                      0.8020709,
                      0.8933256,
                      0.9170977,
                      0.1497008,
                  ],
                  [
                      0.2711633,
                      0.1111478,
                      0.0783281,
                      0.2771807,
                      0.5487481,
                  ],
                  [
                      0.0086008,
                      0.8288748,
                      0.9647092,
                      0.8922020,
                      0.7614344,
                  ],
                  [
                      0.2898048,
                      0.1282895,
                      0.7621747,
                      0.5657831,
                      0.9918593,
                  ],
              ],
              [
                  [
                      0.5414237,
                      0.9962701,
                      0.8947155,
                      0.5900949,
                      0.9483274,
                  ],
                  [
                      0.0468036,
                      0.3933847,
                      0.8046577,
                      0.3640994,
                      0.0632100,
                  ],
                  [
                      0.6171775,
                      0.8624780,
                      0.4126036,
                      0.7600935,
                      0.7279997,
                  ],
                  [
                      0.4237089,
                      0.5365476,
                      0.5591233,
                      0.1523191,
                      0.1382165,
                  ],
                  [
                      0.8932794,
                      0.8517839,
                      0.7152701,
                      0.8983801,
                      0.5905426,
                  ],
              ],
              [
                  [
                      0.2869580,
                      0.4700376,
                      0.2743714,
                      0.8135023,
                      0.2229074,
                  ],
                  [
                      0.9306560,
                      0.3734594,
                      0.4566821,
                      0.7599275,
                      0.7557513,
                  ],
                  [
                      0.7415742,
                      0.6115875,
                      0.3317572,
                      0.0379378,
                      0.1315770,
                  ],
                  [
                      0.8692724,
                      0.0809556,
                      0.7767404,
                      0.8742208,
                      0.1522012,
                  ],
                  [
                      0.7708948,
                      0.4509611,
                      0.0481175,
                      0.2358997,
                      0.6900532,
                  ],
              ],
          ],
          device=device,
          dtype=dtype,
      )
  
      # Output data generated with OpenCV 4.1.1: cv2.cvtColor(img_np, cv2.COLOR_RGB2GRAY)
      expected = torch.tensor(
          [
              [
                  [
                      0.4684734,
                      0.8954562,
                      0.6064363,
                      0.5236061,
                      0.6106016,
                  ],
                  [
                      0.1709944,
                      0.5133104,
                      0.7915002,
                      0.5745703,
                      0.1680204,
                  ],
                  [
                      0.5279005,
                      0.6092287,
                      0.3034387,
                      0.5333768,
                      0.6064113,
                  ],
                  [
                      0.3503858,
                      0.5720159,
                      0.7052018,
                      0.4558409,
                      0.3261529,
                  ],
                  [
                      0.6988886,
                      0.5897652,
                      0.6532392,
                      0.7234108,
                      0.7218805,
                  ],
              ]
          ],
          device=device,
          dtype=dtype,
      )
  
      img_gray = kornia.color.rgb_to_grayscale(data)
      assert_close(img_gray, expected)
  
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 5 for calling the TestRgbToGrayscale obj's underlying member method code with example usage: obj.test_opencv(device, dtype) without return types