code: def operate(self, fromopen):
      if self.order is not None:
          return
      if self.position:
          if self.signal < 0:
              self.order = self.close()
      elif self.signal > 0:
          print(
              "{} Send Buy, fromopen {}, close {}".format(
                  self.data.datetime.date(),
                  fromopen,
                  self.data.close[0],
              )
          )
          self.order = self.buy()
  
file_path: backtrader/samples/cheat-on-open/cheat-on-open.py
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import argparse
  import datetime
  import backtrader
label_desc: Use image node_id 3 for calling the St obj's underlying member method code with example usage: obj.operate(fromopen) without return types