public void updateDesiredRatePerSec(double updatedDesiredRatePerSec) {
        desiredRatePerSec = updatedDesiredRatePerSec;
    }
The throttler takes a desired rate-per-second (the units of the process don't matter, it could be bytes
or a count of some other thing), and will sleep for an appropriate amount of time when maybeThrottle()
is called to attain the desired rate.

@param desiredRatePerSec  The rate we want to hit in units/sec
@param checkIntervalMs    The interval at which to check our rate
@param metricName         The name of the metric
@param units              The name of the unit
@param time               The time implementation to use
storage/src/main/java/org/apache/kafka/storage/internals/utils/Throttler.java