code: def execute_cancel_policy(self, event):
      if self.cancel_policy.should_cancel(event):
          warn = self.cancel_policy.warn_on_cancel
          for asset in copy(self.open_orders):
              self.cancel_all_orders_for_asset(
                  asset, warn, relay_status=False
              )
  
imports: from logbook import Logger
  from collections import defaultdict
  from copy import copy
  from six import iteritems
  from catalyst.assets import Equity, Future, Asset
  from catalyst.finance.order import Order
  from catalyst.finance.slippage import DEFAULT_FUTURE_VOLUME_SLIPPAGE_BAR_LIMIT, VolatilityVolumeShare, VolumeShareSlippage
  from catalyst.finance.commission import DEFAULT_PER_CONTRACT_COST, FUTURE_EXCHANGE_FEES_BY_SYMBOL, PerContract, PerShare
  from catalyst.finance.cancel_policy import NeverCancel
  from catalyst.utils.input_validation import expect_types
  from catalyst.constants import LOG_LEVEL
label_desc: Use image node_id 8 for calling the Blotter obj's underlying member method code with example usage: obj.execute_cancel_policy(event) without return types