private static void gauge(
            String className, String name, long measurement, String... additionalTags) {
        getGauge(className, name, additionalTags).set(measurement);
    }
Set a gauge is a handle to get the current value. Typical examples for gauges would be the
size of a queue or number of threads in the running state. Since gauges are sampled, there is
no information about what might have occurred between samples.

@param className
@param name
@param measurement
@param additionalTags
core/src/main/java/com/netflix/conductor/metrics/Monitors.java