code: def get_musical_key(value: tp.Optional[str]) -> tp.Optional[str]:
      """Preprocess key keywords, discarding them if there are multiple key defined."""
      if (
          value is None
          or (not isinstance(value, str))
          or len(value) == 0
          or value == "None"
      ):
          return None
      elif "," in value:
          # For now, we discard when multiple keys are defined separated with comas
          return None
      else:
          return value.strip().lower()
  
imports: from dataclasses import dataclass, field, fields, replace
  import gzip
  import json
  import logging
  from pathlib import Path
  import random
  import typing
  import torch
  from .info_audio_dataset import InfoAudioDataset, AudioInfo, get_keyword_list, get_keyword, get_string
  from ..modules.conditioners import ConditioningAttributes, JointEmbedCondition, WavCondition
  from ..utils.utils import warn_once
label_desc: Use image node_id 2 for calling a global function with example usage: get_musical_key(value) and returns: None, None, value