code: def _postmortem_traceback(excinfo):
      if isinstance(excinfo.value, UnexpectedException):
          # A doctest.UnexpectedException is not useful for post_mortem.
          # Use the underlying exception instead:
          return excinfo.value.exc_info[2]
      else:
          return excinfo._excinfo[2]
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import os
  import argparse
  import pdb
  import sys
  from doctest import UnexpectedException
  from _pytest import outcomes
  from _pytest.config import hookimpl
  from _pytest.config.exceptions import UsageError
label_desc: Use image node_id 8 for calling a global function with example usage: _postmortem_traceback(excinfo) and returns: excinfo, excinfo