code: def decode(self, _):
      raise Exception("This encoder is not bi-directional")
  
file_path: lightwood/lightwood/encoder/audio/mfcc.py
imports: import librosa
  import torch
  import warnings
  from lightwood.encoder.base import BaseEncoder
  from lightwood.helpers.io import read_from_path_or_url
  from lightwood.helpers.log import log
  from typing import Iterable
label_desc: Use image node_id 4 for calling the MFCCEncoder obj's underlying member method code with example usage: obj.decode(_) without return types