class_docstr: Execution style representing an order to be placed once the market price
  reaches a specified stop price.
code: def get_limit_price(self, _is_buy):
      return None
  
imports: import abc
  from numpy import isfinite
  from six import with_metaclass
  from catalyst.errors import BadOrderParameters
label_desc: Use image node_id 2 for calling the StopOrder obj's underlying member method code with example usage: obj.get_limit_price(_is_buy) and returns: None