code: def __init__(self, seq_len_norm):
      super().__init__()
      self.seq_len_norm = seq_len_norm
  
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 L1LossMasked object from inherited base classes: nn with example: obj = L1LossMasked(seq_len_norm)