docstr: Gets called at the beginning of ``fit()``, on multiple processes
  if ``distributed_count > 0`` and backend is ddp and initializes statistics
docstr_tok: ["Gets","called","at","the","beginning","of","``","fit","(",")","``",",","on","multiple","processes","if","``","distributed_count",">","0","``","and","backend","is","ddp","and","initializes","statistics"]
code: def on_fit_start(self):
      """Gets called at the beginning of ``fit()``, on multiple processes
      if ``distributed_count > 0`` and backend is ddp and initializes statistics
      """
      self.last_epoch = 0
      self.last_batch = None
      self.last_loss_stats = {}
      return super().on_fit_start()
  
file_path: speechbrain/recipes/LibriTTS/vocoder/hifigan/train.py
imports: import sys
  import torch
  from hyperpyyaml import load_hyperpyyaml
  import speechbrain
  from speechbrain.utils.data_utils import scalarize
  import torchaudio
  import os
label_desc: Use image node_id 5 for calling the HifiGanBrain obj's underlying member method code with example usage: obj.on_fit_start() and returns: super