code: def _add_info(self, tar):
      info = tarfile.TarInfo(os.path.basename(INFO_FILE))
      env = self.environment.get_environment_info(include_ext_info=True)
      buf = BytesIO()
      buf.write(json.dumps(env).encode("utf-8"))
      buf.seek(0)
      info.size = len(buf.getvalue())
      # Setting this default to Dec 3, 2019
      info.mtime = 1575360000
      tar.addfile(info, buf)
  
imports: import importlib
  import os
  import sys
  import tarfile
  import time
  import json
  from io import BytesIO
  from .extension_support import EXT_PKG, package_mfext_all
  from .metaflow_config import DEFAULT_PACKAGE_SUFFIXES
  from .exception import MetaflowException
  from .util import to_unicode
  from .None import R, INFO_FILE
label_desc: Use image node_id 4 for calling the MetaflowPackage obj's underlying member method code with example usage: obj._add_info(tar) without return types