presto-main/src/main/java/io/prestosql/server/remotetask/Backoff.java/Backoff/getFailureDuration
class Backoff:    public synchronized Duration getFailureDuration()
    {
        if (firstFailureTime == 0) {
            return new Duration(0, MILLISECONDS);
        }
        long value = ticker.read() - firstFailureTime;
        return new Duration(value, NANOSECONDS);
    }