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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def raw(self, raw):
 """Sets the raw of this RuntimeRawExtension. Raw is the underlying serialization of this object. # noqa: E501 :param raw: The raw of this RuntimeRawExtension. # noqa: E501 :type: str """

        if raw is None:
            raise ValueError("Invalid value for `raw`, must not be `None`")  # noqa: E501
        if raw is not None and not re.search(r'^(?:[A-Za-z0-9+\/]{4})*(?:[A-Za-z0-9+\/]{2}==|[A-Za-z0-9+\/]{3}=)?$', raw):  # noqa: E501
            raise ValueError(r"Invalid value for `raw`, must be a follow pattern or equal to `/^(?:[A-Za-z0-9+\/]{4})*(?:[A-Za-z0-9+\/]{2}==|[A-Za-z0-9+\/]{3}=)?$/`")  # noqa: E501

        self._raw = raw