docs: def execute_side_effect(side_effect=UNDEFINED, args=UNDEFINED, kwargs=UNDEFINED):
      """
      Executes a side effect if one is defined.
  
      :param side_effect: The side effect to execute
      :type side_effect: Mixed. If it's an exception it's raised. If it's callable it's called with teh parameters.
      :param tuple args: The arguments passed to the stubbed out method
      :param dict kwargs: The kwargs passed to the subbed out method.
  
      :rtype: mixed
      :returns: Whatever the passed side_effect returns
      :raises: Whatever error is defined as the side_effect
      """
      if args == UNDEFINED:
          args = tuple()
      if kwargs == UNDEFINED:
          kwargs = {}
      if isinstance(side_effect, (BaseException, Exception, StandardError)):
          raise side_effect
      elif hasattr(side_effect, '__call__'): # If it's callable...
          return side_effect(*args, **kwargs)
      else:
          raise Exception("Caliendo doesn't know what to do with your side effect. {0}".format(side_effect))