class_docstr: Single scale  STFT Loss 
class_docstr_tok: ["Single","scale","STFT","Loss"]
code: def forward(self, y_hat, y):
      y_hat_M = self.stft(y_hat)
      y_M = self.stft(y)
      # magnitude loss
      loss_mag = F.l1_loss(torch.log(y_M), torch.log(y_hat_M))
      # spectral convergence loss
      loss_sc = torch.norm(y_M - y_hat_M, p="fro") / torch.norm(
          y_M, p="fro"
      )
      return loss_mag, loss_sc
  
imports: import torch
  from torch import nn
  from torch.nn import functional
label_desc: Use image node_id 2 for calling the STFTLoss obj's underlying member method code with example usage: obj.forward(y_hat, y) and returns: loss_mag,  loss_sc