def __init__ ( self, allow_none = False ):
        if allow_none:
            self.validate      = self.validate_none
            self.info          = self.info_none
            self.fast_validate = ( 2, None )
        else:
            self.fast_validate = ( 2, )
:param :class:`requests.Response` r: a response object of the Requests
dataset/ETHPy150Open enthought/traits/traits/trait_handlers.py/ThisClass.__init__--crossover with--dataset/ETHPy150Open shichao-an/115wangpan/u115/api.py/RequestHandler._response_parser