public InstantAndValue<T> remove(MetricKey metricKey) {
        return counters.remove(metricKey);
    }
@Test
    public void testRemove() {
        LastValueTracker<Double> lastValueTracker = new LastValueTracker<>();
        lastValueTracker.getAndSet(METRIC_NAME, instant1, 1d);

        assertTrue(lastValueTracker.contains(METRIC_NAME));

        InstantAndValue<Double> result = lastValueTracker.remove(METRIC_NAME);
        assertNotNull(result);
        assertEquals(instant1, result.getIntervalStart());
        assertEquals(1d, result.getValue().longValue());
    }