<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def severity_list(self, severity_list):
 """Sets the severity_list of this Alert. Alert severity list for multi-threshold type. # noqa: E501 :param severity_list: The severity_list of this Alert. # noqa: E501 :type: list[str] """

        allowed_values = ["INFO", "SMOKE", "WARN", "SEVERE"]  # noqa: E501
        if not set(severity_list).issubset(set(allowed_values)):
            raise ValueError(
                "Invalid values for `severity_list` [{0}], must be a subset of [{1}]"  # noqa: E501
                .format(", ".join(map(str, set(severity_list) - set(allowed_values))),  # noqa: E501
                        ", ".join(map(str, allowed_values)))
            )

        self._severity_list = severity_list