code: def get_sequence_key(key, mode):
      """Determines the key to be used for sequences (e.g. graphemes/phonemes)
      based on the naming convention
  
      Arguments
      ---------
      key: str
          the key (e.g. "graphemes", "phonemes")
      mode:
          the mode/sufix (raw, eos/bos)
      """
      return key if mode == "raw" else f"{key}_{mode}"
  
imports: from functools import reduce
  from speechbrain.wordemb.util import expand_to_chars
  import speechbrain
  import torch
  import re
label_desc: Use image node_id 20 for calling a global function with example usage: get_sequence_key(key, mode) and returns: unknown