code: def test_inverse():
      layer = Stft()
      x = torch.randn(2, 400, requires_grad=True)
      y, _ = layer(x)
      x_lengths = torch.IntTensor([400, 300])
      raw, _ = layer.inverse(y, x_lengths)
      raw, _ = layer.inverse(y)
  
imports: import torch
  from espnet2.layers.stft import Stft
label_desc: Use image node_id 5 for calling a global function with example usage: test_inverse() without return types