code: def test_identity_lemmatizer():
      nlp = stanza.Pipeline(
          **{
              "processors": "tokenize,lemma",
              "dir": TEST_MODELS_DIR,
              "lang": "en",
              "lemma_use_identity": True,
          }
      )
      doc = nlp(EN_DOC)
      word_lemma_pairs = []
      for w in doc.iter_words():
          word_lemma_pairs += [f"{w.text} {w.lemma}"]
      assert EN_DOC_IDENTITY_GOLD == "\n".join(word_lemma_pairs)
  
imports: import pytest
  import stanza
  from stanza.tests import *
  from stanza.models.common.doc import TEXT, UPOS, LEMMA
label_desc: Use image node_id 1 for calling a global function with example usage: test_identity_lemmatizer() without return types