code: def exit(self):
      return self.kill_now
  
file_path: catalyst/catalyst/support/issue_216.py
imports: import sys
  import os
  import signal
  import pandas
  from logbook import Logger
  from catalyst import run_algorithm
  from catalyst.api import symbol, record, order
  from catalyst.finance import commission
label_desc: Use image node_id 3 for calling the GracefulKiller obj's underlying member method code with example usage: obj.exit() and returns: self