quantopian/zipline — pull request #327 by ssanderson (2014-04-28 21:38:28+00:00)
Title: ENH: Add the ability to specify an exchange on an ExecutionStyle.

Adds `get_exchange` to the required interface for any ExecutionStyle, and adds
an exchange parameter to the interface of all the existing ExceutionStyles.

A simple default implementation of get_exchange is provided by the
ExchangeGetterMixin class.