code: def llama_tokenizer():
      try:
          return LlamaTokenizer.from_pretrained(
              "meta-llama/Llama-2-7b-hf"
          )
      except OSError as e:
          if unskip_missing_tokenizer:
              raise e
      return None
  
imports: import pytest
  from transformers import LlamaTokenizer
label_desc: Use image node_id 1 for calling a global function with example usage: llama_tokenizer() and returns: None, LlamaTokenizer