@Test
public void testBuckets() throws Exception {

    WindowedMapGauge<Long> gauge = new WindowedMapGauge<>("wtf", 60000L, Long::max);
    assertEquals(new WindowedMapGauge.Windows(0L, -60000L), gauge.getWindowStartTimes(0L));
    assertEquals(new WindowedMapGauge.Windows(0L, -60000L), gauge.getWindowStartTimes(1L));
    assertEquals(new WindowedMapGauge.Windows(0L, -60000L) , gauge.getWindowStartTimes(59999L));
    assertEquals(new WindowedMapGauge.Windows(60000L, 0L), gauge.getWindowStartTimes(60000L));
    assertEquals(new WindowedMapGauge.Windows(300000L, 240000L), gauge.getWindowStartTimes(300001L));
}