class_docstr: Test ByteLevelBPE is well-behaved.
class_docstr_tok: ["Test","ByteLevelBPE","is","well-behaved","."]
docstr: Save and reload an existing BL-BPE dictionary.
code: def test_save_reload(self):
      """
      Save and reload an existing BL-BPE dictionary.
      """
      pp = ParlaiParser()
      DictionaryAgent.add_cmdline_args(pp, partial_opt=None)
      da = DictionaryAgent(
          pp.parse_args(
              [
                  "--dict-tokenizer",
                  "bytelevelbpe",
                  "--bpe-merge",
                  DEFAULT_BYTELEVEL_BPE_MERGE,
                  "--bpe-vocab",
                  DEFAULT_BYTELEVEL_BPE_VOCAB,
              ]
          )
      )
      # poor behavior if we failed to load
      assert da.txt2vec("hello") != []
  
      with testing_utils.tempdir() as tmpdir:
          newdf = os.path.join(tmpdir, "dict")
          da.save(newdf)
  
          # now load it
          da2 = DictionaryAgent(
              pp.parse_args(
                  [
                      "--dict-tokenizer",
                      "bytelevelbpe",
                      "--dict-file",
                      newdf,
                  ]
              )
          )
          assert da2.txt2vec("hello") == da.txt2vec("hello")
  
imports: from parlai.core.build_data import modelzoo_path
  from parlai.core.dict import find_ngrams
  from parlai.core.params import ParlaiParser
  from parlai.core.dict import DictionaryAgent, TokenizationMode
  from parlai.core.opt import Opt
  import parlai.scripts.build_dict
  from parlai.utils.io import PathManager
  import parlai.utils.testing
  import os
  import shutil
  import unittest
  import pytest
label_desc: Use image node_id 4 for calling the TestByteLevelBPE obj's underlying member method code with example usage: obj.test_save_reload() without return types