code: def trace(
      arg: Union[bool, TextIO, str, os.PathLike] = None,
      *,
      mode: str = "a",
  ) -> None:
      """print a trace through the stack when pickling; useful for debugging
  
      With a single boolean argument, enable or disable the tracing.
  
      Example usage:
  
          >>> import dill
          >>> dill.detect.trace(True)
          >>> dill.dump_session()
  
      Alternatively, ``trace()`` can be used as a context manager. With no
      arguments, it just takes care of restoring the tracing state on exit.
      Either a file handle, or a file name and (optionally) a file mode may be
      specitfied to redirect the tracing output in the ``with`` block context. A
      log function is yielded by the manager so the user can write extra
      information to the file.
  
      Example usage:
  
          >>> from dill import detect
          >>> D = {'a': 42, 'b': {'x': None}}
          >>> with detect.trace():
          >>>     dumps(D)
          ┬ D2: <dict object at 0x7f2721804800>
          ├┬ D2: <dict object at 0x7f27217f5c40>
          │└ # D2 [8 B]
          └ # D2 [22 B]
          >>> squared = lambda x: x**2
          >>> with detect.trace('output.txt', mode='w') as log:
          >>>     log("> D = %r", D)
          >>>     dumps(D)
          >>>     log("> squared = %r", squared)
          >>>     dumps(squared)
  
      Arguments:
          arg: a boolean value, or an optional file-like or path-like object for the context manager
          mode: mode string for ``open()`` if a file name is passed as the first argument
      """
      if not isinstance(arg, bool):
          return TraceManager(file=arg, mode=mode)
      logger.setLevel(logging.INFO if arg else logging.WARNING)
  
imports: import codecs
  import contextlib
  import locale
  import logging
  import math
  import os
  from functools import partial
  from typing import TextIO, Union
  import dill
label_desc: Use image node_id 1 for calling a global function with example usage: trace(arg) and returns: TraceManager