code: def extra_repr(self):
      return f"norm_means={self.norm_means}, norm_vars={self.norm_vars}"
  
imports: from typing import List, Tuple, Union
  import librosa
  import numpy
  import torch
  from torch_complex.tensor import ComplexTensor
  from espnet.nets.pytorch_backend.nets_utils import make_pad_mask
label_desc: Use image node_id 2 for calling the UtteranceMVN obj's underlying member method code with example usage: obj.extra_repr() and returns: str, self, str, self