def __init__(self, message, scene=None):
        self._scene = scene
        self._message = message
Get mapper handler instance.
dataset/ETHPy150Open peterbrittain/asciimatics/asciimatics/exceptions.py/ResizeScreenError.__init__--crossover with--dataset/ETHPy150Open AppScale/appscale/AppServer/google/appengine/ext/mapreduce/model.py/MapperSpec.get_handler