code: def handle_commission(self, asset, cost):
      # Adjust the cost basis of the stock if we own it
      if asset in self.positions:
          self.positions[asset].adjust_commission_cost_basis(
              asset, cost
          )
  
imports: from __future__ import division
  import logbook
  import numpy
  from collections import namedtuple
  from math import isnan
  from six import iteritems, itervalues
  from catalyst.finance.performance.position import Position
  from catalyst.finance.transaction import Transaction
  from catalyst.utils.input_validation import expect_types
  import catalyst.protocol
  from catalyst.assets import Future, Asset
  from .position import positiondict
  from catalyst.constants import LOG_LEVEL
label_desc: Use image node_id 4 for calling the PositionTracker obj's underlying member method code with example usage: obj.handle_commission(asset, cost) without return types