### Question:
LongTaskTimer implements com.netflix.spectator.api.LongTaskTimer { @Override public long start() { long task = nextTask.getAndIncrement(); tasks.put(task, clock.monotonicTime()); return task; } private  LongTaskTimer(Registry registry, Id id); static LongTaskTimer get(Registry registry, Id id); @Override Id id(); @Override boolean hasExpired(); @Override long start(); @Override long stop(long task); @Override long duration(long task); @Override long duration(); @Override int activeTasks(); @Override Iterable<Measurement> measure();  }### Answer:
@Test public void testStart() { com.netflix.spectator.api.LongTaskTimer t = LongTaskTimer.get(registry, id); long task1 = t.start(); long task2 = t.start(); Assertions.assertNotEquals(task1, task2); Assertions.assertEquals(t.activeTasks(), 2); Assertions.assertEquals(t.duration(), 0L); }