@Test
    void testMixedActivity() {
        TimeTracker t = new TimeTracker(new Chain<Searcher>(
                new UselessSearcher("first"), new UselessSearcher("second"),
                new UselessSearcher("third")));
        runSomeTraffic(t);

        SearcherTimer[] searchers = t.searcherTracking();
        assertEquals(Long.valueOf(1L), searchers[0].getInvoking(Activity.SEARCH));
        assertNull(searchers[0].getInvoking(Activity.FILL));
        assertEquals(Long.valueOf(2L), searchers[0].getReturning(Activity.SEARCH));
        assertEquals(Long.valueOf(2L), searchers[0].getReturning(Activity.FILL));

        assertEquals(Long.valueOf(2L), searchers[1].getInvoking(Activity.SEARCH));
        assertEquals(Long.valueOf(2L), searchers[1].getInvoking(Activity.FILL));
        assertEquals(Long.valueOf(2L), searchers[1].getReturning(Activity.SEARCH));
        assertEquals(Long.valueOf(2L), searchers[1].getReturning(Activity.FILL));

        assertEquals(Long.valueOf(2L), searchers[2].getInvoking(Activity.SEARCH));
        assertEquals(Long.valueOf(2L), searchers[2].getInvoking(Activity.FILL));
        assertNull(searchers[2].getReturning(Activity.SEARCH));
        assertNull(searchers[2].getReturning(Activity.FILL));
    }
Check sanity of TimeTracker and ElapsedTime.

@author Steinar Knutsen
container-search/src/test/java/com/yahoo/search/statistics/ElapsedTimeTestCase.java