code: def __init__(self, context):
      self.kill_now = False
      self.signal = 0
      self.context = context
      signal.signal(signal.SIGINT, self.exit_gracefully)
  
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 1 to create a new GracefulKiller object  with example: obj = GracefulKiller(context)