def raw(self, raw):
        """
        Sets the raw of this RuntimeRawExtension.
        Raw is the underlying serialization of this object.

        :param raw: The raw of this RuntimeRawExtension.
        :type: str
        """
        if raw is None:
            raise ValueError("Invalid value for `raw`, must not be `None`")
        if raw is not None and not re.search('^(?:[A-Za-z0-9+\/]{4})*(?:[A-Za-z0-9+\/]{2}==|[A-Za-z0-9+\/]{3}=)?$', raw):
            raise ValueError("Invalid value for `raw`, must be a follow pattern or equal to `/^(?:[A-Za-z0-9+\/]{4})*(?:[A-Za-z0-9+\/]{2}==|[A-Za-z0-9+\/]{3}=)?$/`")

        self._raw = raw