code: def next(self):
      if self.crossover > 0:
          self.buy()
  
      elif self.crossover < 0:
          self.sell()
  
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 2 for calling the CloseSMA obj's underlying member method code with example usage: obj.next() without return types