def from_json(self, json, models=None):
        if json is None:
            return None
        elif isinstance(json, dict):
            return { self.keys_type.from_json(key, models): self.values_type.from_json(value, models) for key, value in iteritems(json) }
        else:
            raise DeserializationError((self, json) % "%s expected a dict or None, got %s")
dataset/ETHPy150Open bokeh/bokeh/bokeh/core/properties.py/Dict.from_json/swapped operands of `%`