appengine.py 文件源码

def _validate(self, value):
            """Validates a value as a proper credentials object.

            Args:
                value: A value to be set on the property.

            Raises:
                TypeError if the value is not an instance of Credentials.
            """
            logger.info('validate: Got type %s', type(value))
            if value is not None and not isinstance(value, Credentials):
                raise TypeError('Property %s must be convertible to a '
                                'credentials instance; received: %s.' %
                                (self._name, value))