code: def check_language_codes(self):
      self.assertEqual(
          self.tokenizer.fairseq_tokens_to_ids["ar_AR"], 250001
      )
      self.assertEqual(
          self.tokenizer.fairseq_tokens_to_ids["en_EN"], 250004
      )
      self.assertEqual(
          self.tokenizer.fairseq_tokens_to_ids["ro_RO"], 250020
      )
  
imports: import shutil
  import tempfile
  import unittest
  from transformers import SPIECE_UNDERLINE, BatchEncoding, MBartTokenizer, MBartTokenizerFast, is_torch_available
  from transformers.testing_utils import get_tests_dir, nested_simplify, require_sentencepiece, require_tokenizers, require_torch
  from ...test_tokenization_common import TokenizerTesterMixin
label_desc: Use image node_id 2 for calling the MBartEnroIntegrationTest obj's underlying member method code with example usage: obj.check_language_codes() without return types