@Test
public void testSingleInputIncreasingWatermarks() {

	BufferedValveOutputHandler valveOutput = new BufferedValveOutputHandler();
	StatusWatermarkValve valve = new StatusWatermarkValve(1, valveOutput);
	valve.inputWatermark(new Watermark(0), 0);
	assertEquals(new Watermark(0), valveOutput.popLastSeenOutput());
	assertEquals(null, valveOutput.popLastSeenOutput());
	valve.inputWatermark(new Watermark(25), 0);
	assertEquals(new Watermark(25), valveOutput.popLastSeenOutput());
	assertEquals(null, valveOutput.popLastSeenOutput());
}