code: def test_unit(self, device, dtype, aval):
      data = torch.tensor(
          [
              [
                  [[1.0, 1.0], [1.0, 1.0]],
                  [[2.0, 2.0], [2.0, 2.0]],
                  [[3.0, 3.0], [3.0, 3.0]],
              ]
          ],
          device=device,
          dtype=dtype,
      )  # Bx3x2x2
  
      expected = torch.tensor(
          [
              [
                  [[1.0, 1.0], [1.0, 1.0]],
                  [[2.0, 2.0], [2.0, 2.0]],
                  [[3.0, 3.0], [3.0, 3.0]],
                  [[aval, aval], [aval, aval]],
              ]
          ],
          device=device,
          dtype=dtype,
      )  # Bx4x2x2
  
      self.assert_close(kornia.color.rgb_to_rgba(data, aval), expected)
  
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 TestRgbToRgba obj's underlying member method code with example usage: obj.test_unit(device, dtype, aval) without return types