code: def freeze_optimizers(self, optimizers):
      """Freezes the wav2vec2 optimizer according to the warmup steps"""
      valid_optimizers = {}
      if not self.hparams.wav2vec2.freeze:
          valid_optimizers["wav2vec_optimizer"] = optimizers[
              "wav2vec_optimizer"
          ]
      valid_optimizers["model_optimizer"] = optimizers[
          "model_optimizer"
      ]
      return valid_optimizers
  
imports: import functools
  import os
  import sys
  from pathlib import Path
  import torch
  import logging
  import speechbrain
  import torchaudio
  from hyperpyyaml import load_hyperpyyaml
  from speechbrain.tokenizers.SentencePiece import SentencePiece
  from speechbrain.utils.data_utils import undo_padding
  from speechbrain.utils.distributed import run_on_main, if_main_process
label_desc: Use image node_id 1 for calling a global function with example usage: freeze_optimizers(optimizers) and returns: valid_optimizers