code: def read_audio(self, path, ref_len=None):
      wav, sr = sf.read(path)
      assert sr == self.task.cfg.sample_rate, sr
      if wav.ndim == 2:
          wav = wav.mean(-1)
      assert wav.ndim == 1, wav.ndim
      if ref_len is not None and abs(ref_len - len(wav)) > 160:
          logging.warning(f"ref {ref_len} != read {len(wav)} ({path})")
      return wav
  
file_path: fairseq/examples/hubert/simple_kmeans/dump_w2v2_feature.py
imports: import logging
  import os
  import sys
  import fairseq
  import soundfile
  import torch
  import torch.nn.functional
  from feature_utils import get_path_iterator, dump_feature
label_desc: Use image node_id 2 for calling the Wav2Vec2FeatureReader obj's underlying member method code with example usage: obj.read_audio(path, ref_len) and returns: wav