class_docstr: Multi scale STFT loss 
class_docstr_tok: ["Multi","scale","STFT","loss"]
code: def forward(self, y_hat, y):
      N = len(self.loss_funcs)
      loss_sc = 0
      loss_mag = 0
      for f in self.loss_funcs:
          lm, lsc = f(y_hat, y)
          loss_mag += lm
          loss_sc += lsc
      loss_sc /= N
      loss_mag /= N
      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 MultiScaleSTFTLoss obj's underlying member method code with example usage: obj.forward(y_hat, y) and returns: loss_mag,  loss_sc