private void setMaxTrendRange(int trendRange) {
        if (trendRange > maxTrendRange) {
            maxTrendRange = trendRange;
        }
    }
Used for verify the alarm expression and get the metrics name when read the alarm rules.
oap-server/server-alarm-plugin/src/main/java/org/apache/skywalking/oap/server/core/alarm/provider/expr/rt/AlarmMQEVerifyVisitor.java