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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 triggers(self, triggers):
 """Sets the triggers of this Notificant. A list of occurrences on which this webhook will be fired. Valid values are ALERT_OPENED, ALERT_UPDATED, ALERT_RESOLVED, ALERT_MAINTENANCE, ALERT_SNOOZED # noqa: E501 :param triggers: The triggers of this Notificant. # noqa: E501 :type: list[str] """

        if triggers is None:
            raise ValueError("Invalid value for `triggers`, must not be `None`")  # noqa: E501
        allowed_values = ["ALERT_OPENED", "ALERT_UPDATED", "ALERT_RESOLVED", "ALERT_MAINTENANCE", "ALERT_SNOOZED", "ALERT_INVALID", "ALERT_NO_LONGER_INVALID", "ALERT_TESTING", "ALERT_RETRIGGERED", "ALERT_NO_DATA", "ALERT_NO_DATA_RESOLVED", "ALERT_NO_DATA_MAINTENANCE", "ALERT_SERIES_SEVERITY_UPDATE", "ALERT_SEVERITY_UPDATE"]  # noqa: E501
        if not set(triggers).issubset(set(allowed_values)):
            raise ValueError(
                "Invalid values for `triggers` [{0}], must be a subset of [{1}]"  # noqa: E501
                .format(", ".join(map(str, set(triggers) - set(allowed_values))),  # noqa: E501
                        ", ".join(map(str, allowed_values)))
            )

        self._triggers = triggers