void clearCounter(String counterName) {
		final Counter counter = getCounterByName(counterName);
		if (counter != null) {
			final List<CounterRequest> requests = counter.getRequests();
			// on réinitialise le counter
			counter.clear();
			// et on purge les données correspondantes du collector utilisées pour les deltas
			globalRequestsByCounter.remove(counter);
			for (final CounterRequest request : requests) {
				requestsById.remove(request.getId());
				requestJRobinsById.remove(request.getId());
			}
		}
	}
@Test
	public void testClearCounter() {
		final Counter counter = createCounter();
		final Collector collector = new Collector("test collector",
				Collections.singletonList(counter));
		counter.addRequest("test clear", 0, 0, 0, false, 1000);
		collector.clearCounter(counter.getName());
		if (counter.getRequestsCount() != 0) {
			fail("counter vide");
		}
		collector.clearCounter("nothing");
	}