def validate(self):
        """
        validate the RevocationReason object
        """
        if not isinstance(self.revocation_code, RevocationReasonCode):
            msg = "RevocationReaonCode expected"
            raise TypeError(msg)
        if self.revocation_message is not None:
            if not isinstance(self.revocation_message, TextString):
                msg = "TextString expect"
                raise TypeError(msg)
validate the RevocationReason object