code: def _safe(self, obj):
      from parlai.core.message import Message
  
      if isinstance(obj, list):
          return [self._safe(o) for o in obj]
      elif isinstance(obj, Message):
          obj = dict(obj)
          for key in ["label_candidates", "eval_label_candidates"]:
              if key not in obj:
                  continue
              if isinstance(obj[key], set):
                  obj[key] = sorted(list(obj[key]))
              if len(obj[key]) > 20:
                  obj[key] = list(obj[key][:10]) + list(obj[key][-10:])
          if "image" in obj:
              # convert the image to base64 encoding so we can store it as a string
              import base64
              import PIL
  
              assert isinstance(obj["image"], PIL.Image.Image)
              resized = obj["image"].resize((16, 16), PIL.Image.NEAREST)
              gray = resized.convert("LA")
              obj["image_hex"] = base64.b64encode(
                  gray.tobytes()
              ).decode("ascii")
              del obj["image"]
          return obj
      else:
          return obj
  
imports: import os
  import unittest
  import contextlib
  import tempfile
  import shutil
  import io
  import signal
  from typing import Tuple, Dict, Any
  from parlai.core.opt import Opt
  import parlai.utils.logging
  from parlai.utils.io import PathManager
  from pytest_regressions.data_regression import DataRegressionFixture
label_desc: Use image node_id 1 for calling the AutoTeacherTest obj's underlying member method code with example usage: obj._safe(obj) and returns: unknown, obj, obj