class_docstr: Base class for order execution styles.
      
class_docstr_tok: ["Base","class","for","order","execution","styles","."]
docstr: The exchange to which this order should be routed.
docstr_tok: ["The","exchange","to","which","this","order","should","be","routed","."]
code: def exchange(self):
      """
      The exchange to which this order should be routed.
      """
      return self._exchange
  
imports: import abc
  from sys import float_info
  from six import with_metaclass
  from numpy import isfinite
  import zipline.utils.math_utils
  from zipline.errors import BadOrderParameters
  from zipline.utils.compat import consistent_round
label_desc: Use image node_id 3 for calling the ExecutionStyle obj's underlying member method code with example usage: obj.exchange() and returns: self