docstr: Build a new model instance.
docstr_tok: ["Build","a","new","model","instance","."]
code: def build_model(
      cls, cfg: AudioClassificationConfig, task: FairseqTask
  ):
      """Build a new model instance."""
  
      assert hasattr(
          task, "labels"
      ), f"Task {task} must have an attribute 'labels'"
  
      return cls(cfg, len(task.labels))
  
imports: import contextlib
  import logging
  import re
  from dataclasses import dataclass, field
  from typing import Any, Optional
  import torch
  import torch.nn
  import torch.nn.functional
  import numpy
  from omegaconf import II, MISSING, open_dict
  from fairseq import checkpoint_utils, tasks
  from fairseq.dataclass import FairseqDataclass
  from fairseq.dataclass.utils import convert_namespace_to_omegaconf
  from fairseq.models import BaseFairseqModel, register_model
  from fairseq.models.wav2vec.wav2vec2 import MASKING_DISTRIBUTION_CHOICES
  from fairseq.modules import TransposeLast
  from fairseq.tasks import FairseqTask
label_desc: Use image node_id 3 for calling the AudioClassificationModel obj's underlying member method code with example usage: obj.build_model(cls, cfg, task) and returns: cls