class_docstr: Differential Spectral Loss
  https://arxiv.org/ftp/arxiv/papers/1909/1909.10302.pdf
code: def __init__(self, loss_func):
      super().__init__()
      self.loss_func = loss_func
  
imports: import math
  import numpy
  import torch
  from torch import nn
  from inspect import signature
  from torch.nn import functional
  from TTS.tts.utils.generic_utils import sequence_mask
  from TTS.tts.utils.ssim import ssim
label_desc: Use image node_id 1 to create a new DifferentailSpectralLoss object from inherited base classes: nn with example: obj = DifferentailSpectralLoss(loss_func)