@Override
    public Map<Long, T> loadAll(Collection<Long> keys) {
        long startNanos = Timer.nanos();
        try {
            return delegate.loadAll(keys);
        } finally {
            loadAllProbe.recordValue(Timer.nanosElapsed(startNanos));
        }
    }
@Test
    public void loadAll() {
        Collection<Long> keys = Arrays.asList(1L, 2L);
        Map<Long, String> values = new HashMap<>();
        values.put(1L, "value1");
        values.put(2L, "value2");

        when(delegate.loadAll(keys)).thenReturn(values);

        Map<Long, String> result = queueStore.loadAll(keys);

        assertEquals(values, result);
        assertProbeCalledOnce("loadAll");
    }