private void enteringState(int searcherIndex, boolean detailed, final Activity activity) {
        long now = 0L;
        if (detailed) {
            now = detailedMeasurements(searcherIndex, true);
        }
        if (isNewState(activity)) {
            if (now == 0L) {
                now = getNow();
            }
            concludeState(now);
            initNewState(now, activity);
        }
    }
A container for storing time stamps throughout the lifetime of an Execution instance.

<p>Check state both when entering and exiting, to allow for arbitrary
new queries anywhere inside a search chain.

@author Steinar Knutsen
container-search/src/main/java/com/yahoo/search/statistics/TimeTracker.java