Test NiFi StopWatch class - demonstrates bug at NIFI-5742

TestStopWatch.java

import org.apache.nifi.util.StopWatch;

import java.util.concurrent.TimeUnit;

class Scratch {

    // https://github.com/apache/nifi/blob/02261311b3b3f765ebb394f8f101b0373a7fb3ab/nifi-commons/nifi-utils/src/main/java/org/apache/nifi/util/StopWatch.java#L77
    public static void main(String[] args) {
        StopWatch stopWatch = new StopWatch(true);

        try {
            Thread.sleep(250);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        long millsSince = stopWatch.getElapsed(TimeUnit.MILLISECONDS);
        System.out.println(millsSince);

        try {
            Thread.sleep(250);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        stopWatch.stop();
        millsSince = stopWatch.getElapsed(TimeUnit.MILLISECONDS);
        System.out.println(millsSince);
    }
}

The test class prints the following:

252
1897579286