public Level getLevelLimit() {
        Level lvl;
        if (isOn(LogLevel.LogCtlSPAM)) {
            lvl = LogLevel.ALL;
        } else if (isOn(LogLevel.LogCtlDEBUG)) {
            lvl = LogLevel.FINE;
        } else if (isOn(LogLevel.LogCtlCONFIG)) {
            lvl = LogLevel.CONFIG;
        } else if (isOn(LogLevel.LogCtlINFO)) {
            lvl = LogLevel.INFO;
        } else if (isOn(LogLevel.LogCtlWARNING)) {
            lvl = LogLevel.WARNING;
        } else {
            lvl = LogLevel.SEVERE;
        }
        return lvl;
    }
make sure our associated java.util.Logger instance
gets the correct logging level so it can avoid sending
us lots of debug and spam log messages that will
be discarded in the usual case.
vespalog/src/main/java/com/yahoo/log/MappedLevelController.java