code: def _getsizing(self, comminfo, cash, data, isbuy):
      position = self.strategy.getposition(data)
      size = self.p.stake * (1 + (position.size != 0))
      return size
  
file_path: backtrader/samples/sizertest/sizertest.py
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import argparse
  import datetime
  import random
  import backtrader
label_desc: Use image node_id 1 for calling the FixedReverser obj's underlying member method code with example usage: obj._getsizing(comminfo, cash, data, isbuy) and returns: size