public <E extends SamplingEntry> Iterable<E> getRandomSamples(int sampleCount) {
        if (sampleCount < 0) {
            throw new IllegalArgumentException("Sample count cannot be a negative value.");
        }
        if (sampleCount == 0 || size() == 0) {
            return Collections.emptyList();
        }
        return new LazySamplingEntryIterableIterator<>(sampleCount);
    }
@Test(expected = IllegalArgumentException.class)
    public void test_getRandomSamples_whenSampleCountIsNegative() {
        map = new SampleableConcurrentHashMap<>(10);

        map.getRandomSamples(-1);
    }