@Override
    public String toString() {
        return "{" +
                "\"elapsedNanoTime\"=" + elapsedNanoTime +
                ", \"elapsedTime\"=" + getElapsedTime() +
                '}';
    }
Returns the elapsed time in milliseconds.
@return
client-v2/src/main/java/com/clickhouse/client/api/internal/StopWatch.java