code: def test_frontend_forward():
      frontend = SlidingWindow(
          fs=160, win_length=32, hop_length=32, padding=0
      )
      x = torch.randn(2, 300, requires_grad=True)
      x_lengths = torch.LongTensor([300, 89])
      y, y_lengths = frontend(x, x_lengths)
      y.sum().backward()
      # check for correct output lengths
      # needs change if padding applied!
      assert all(y_lengths == torch.tensor([9, 2]))
      assert y.shape == torch.Size([2, 9, 1, 32])
  
label_desc: Use image node_id 2 for calling a global function with example usage: test_frontend_forward() without return types