docs: def _execute(task):
    """A wrapper around exec
  
    This exists outside the Scheduler class because it is pickled after it is
    sent to the executor.
    """
    print "[%s] -- %s -- START" % (datetime.datetime.now(), task['id'])
    try:
      with get_app().app_context():
        exec task['code'] in {}, {}
        print "[%s] -- %s -- COMPLETE" % (datetime.datetime.now(), task['id'])
    except Exception as e:
      if isinstance(e, PyCodeError):
        err_msg = "%s: %s\n%s" % (e.data['name'], e.data['message'],
                                  ''.join(e.data['traceback']))
      else:
        err_msg = traceback.format_exc()
      sys.stderr.write(err_msg)
      sys.stderr.write("[%s] -- %s -- FAIL\n" % (datetime.datetime.now(),
                                                 task['id']))
      email_msg = 'Task %s failed at %s\n\n%s' % (task['id'],
                                                  datetime.datetime.now(),
                                                  err_msg)
      send_mail(get_app().config['SCHEDULER_FAILURE_EMAILS'],
                'Scheduler Failure', email_msg)
    finally:
      return task