code: def find_unknown_word(lemmatizer, base):
      for i in range(10):
          base = base + "z"
          if base not in lemmatizer.word_dict and all(
              x[0] != base for x in lemmatizer.composite_dict.keys()
          ):
              return base
      raise RuntimeError("wtf?")
  
imports: import pytest
  import stanza
  from stanza.tests import *
  from stanza.models.common.doc import TEXT, UPOS, LEMMA
label_desc: Use image node_id 3 for calling a global function with example usage: find_unknown_word(lemmatizer, base) and returns: base