public Map<Periodical, ScheduledFuture> getFutures() {
        return Maps.newHashMap(futures);
    }
@Test
    public void testGetFutures() throws Exception {
        periodicals.registerAndStart(periodical);

        assertTrue("missing periodical in future Map", periodicals.getFutures().containsKey(periodical));
        assertEquals(1, periodicals.getFutures().size());
    }