code: def char_vocabulary():
      return [" ", "a", "b", "c", "d", "e", "f"]
  
file_path: NeMo/tests/collections/asr/decoding/test_ctc_decoding.py
imports: import os
  from functools import lru_cache
  import pytest
  import torch
  from omegaconf import DictConfig, OmegaConf
  from nemo.collections.asr.parts.mixins import mixins
  from nemo.collections.asr.parts.submodules.ctc_decoding import CTCBPEDecoding, CTCBPEDecodingConfig, CTCDecoding, CTCDecodingConfig
  from nemo.collections.asr.parts.utils.rnnt_utils import Hypothesis
label_desc: Use image node_id 1 for calling a global function with example usage: char_vocabulary() and returns: list