code: def treebank_to_short_name(treebank):
      """Convert treebank name to short code."""
      if treebank in treebank_special_cases:
          return treebank_special_cases.get(treebank)
      if SHORTNAME_RE.match(treebank):
          lang, corpus = treebank.split("_", 1)
          lang = lang_to_langcode(lang)
          return lang + "_" + corpus
  
      if treebank.startswith("UD_"):
          treebank = treebank[3:]
      # special case starting with zh in case the input is an already-converted ZH treebank
      if treebank.startswith("zh-hans") or treebank.startswith(
          "zh-hant"
      ):
          splits = (
              treebank[: len("zh-hans")],
              treebank[len("zh-hans") + 1 :],
          )
      else:
          splits = treebank.split("-")
          if len(splits) == 1:
              splits = treebank.split("_", 1)
      assert len(splits) == 2, "Unable to process %s" % treebank
      lang, corpus = splits
  
      lcode = lang_to_langcode(lang)
  
      short = "{}_{}".format(lcode, corpus.lower())
      return short
  
imports: import re
label_desc: Use image node_id 5 for calling a global function with example usage: treebank_to_short_name(treebank) and returns: short, treebank_special_cases, unknown