docstr: We need to test downgrade adapter for version >= FIRST_DOWNGRADE_ADAPTER_VERSION
docstr_tok: ["We","need","to","test","downgrade","adapter","for","version",">","=","FIRST_DOWNGRADE_ADAPTER_VERSION"]
code: def test_all_downgrade_adapters_exist(self):
      """
      We need to test downgrade adapter for version >= FIRST_DOWNGRADE_ADAPTER_VERSION
      """
      for i, v in enumerate(sorted(DOWNGRADE_ADAPTERS.keys())):
          self.assertEqual(
              i + FIRST_DOWNGRADE_ADAPTER_VERSION,
              v,
              f"Missing downgrade adapter for version {v}",
          )
  
file_path: pytext/pytext/config/test/config_adapter_test.py
imports: import glob
  import json
  import os
  import unittest
  from pytext.builtin_task import register_builtin_tasks
  from pytext.config import LATEST_VERSION, pytext_config_from_json
  from pytext.config.config_adapter import ADAPTERS, DOWNGRADE_ADAPTERS, downgrade_one_version, upgrade_one_version
  from pytext.utils.file_io import PathManager
label_desc: Use image node_id 2 for calling the ConfigAdapterTest obj's underlying member method code with example usage: obj.test_all_downgrade_adapters_exist() without return types