docstr: Override to prevent this from running for D training
docstr_tok: ["Override","to","prevent","this","from","running","for","D","training"]
code: def on_fit_start(self):
      "Override to prevent this from running for D training"
      if self.sub_stage == SubStage.GENERATOR:
          super().on_fit_start()
  
imports: import os
  import sys
  import shutil
  import pickle
  import torch
  import torchaudio
  import speechbrain
  from pesq import pesq
  from enum import Enum, auto
  from hyperpyyaml import load_hyperpyyaml
  from speechbrain.utils.metric_stats import MetricStats
  from speechbrain.processing.features import spectral_magnitude
  from speechbrain.nnet.loss.stoi_loss import stoi_loss
  from speechbrain.utils.distributed import run_on_main
  from speechbrain.dataio.sampler import ReproducibleWeightedRandomSampler
label_desc: Use image node_id 15 for calling the MetricGanBrain obj's underlying member method code with example usage: obj.on_fit_start() without return types