def validate(self, value):
        super(Either, self).validate(value)

        if not (value is None or any(param.is_valid(value) for param in self.type_params)):
            raise ValueError("expected an element of either %s, got %r" % (nice_join(self.type_params), value))
dataset/ETHPy150Open bokeh/bokeh/bokeh/core/properties.py/Either.validate/original