presto-main/src/main/java/io/prestosql/execution/QueryStateTimer.java/QueryStateTimer/QueryStateTimer
class QueryStateTimer:    public QueryStateTimer(Ticker ticker)
    {
        this.ticker = requireNonNull(ticker, "ticker is null");
        this.createNanos = tickerNanos();
        this.lastHeartbeatNanos = new AtomicReference<>(createNanos);
    }