code: def test_ssim_variable_channel(available_device):
      y_preds = [
          torch.rand(12, 5, 28, 28, device=available_device),
          torch.rand(12, 4, 28, 28, device=available_device),
          torch.rand(12, 7, 28, 28, device=available_device),
          torch.rand(12, 3, 28, 28, device=available_device),
          torch.rand(12, 11, 28, 28, device=available_device),
          torch.rand(12, 6, 28, 28, device=available_device),
      ]
      y_true = [v * 0.8 for v in y_preds]
  
      for y_pred, y in zip(y_preds, y_true):
          compare_ssim_ignite_skiimg(y_pred, y, available_device)
  
file_path: ignite/tests/ignite/metrics/test_ssim.py
imports: from typing import Sequence, Union
  import numpy
  import pytest
  import torch
  from skimage.metrics import structural_similarity
  import ignite.distributed
  from ignite.exceptions import NotComputableError
  from ignite.metrics import SSIM
label_desc: Use image node_id 7 for calling a global function with example usage: test_ssim_variable_channel(available_device) without return types