code: def load_source_vocabs(folder: str) -> List[Vocab]:
      """
      Loads source vocabularies from folder. The first element in the list is the primary source vocabulary.
      Other elements correspond to optional additional source factor vocabularies found in folder.
  
      :param folder: Source folder.
      :return: List of vocabularies.
      """
      return [
          vocab_from_json(os.path.join(folder, fname))
          for fname in _get_sorted_source_vocab_fnames(folder)
      ]
  
imports: import argparse
  import json
  import logging
  import os
  from collections import Counter
  from itertools import chain, islice
  from typing import Dict, Iterable, List, Optional, Tuple, Callable
  from sockeye.log import setup_main_logger
  from .None import constants
  from .None import utils
label_desc: Use image node_id 13 for calling a global function with example usage: load_source_vocabs(folder) and returns: unknown